diff --git a/esphome/components/api/api_pb2.cpp b/esphome/components/api/api_pb2.cpp
index 98bea30628..febc2927d9 100644
--- a/esphome/components/api/api_pb2.cpp
+++ b/esphome/components/api/api_pb2.cpp
@@ -79,7 +79,7 @@ void SerialProxyInfo::encode(ProtoWriteBuffer &buffer) const {
 uint32_t SerialProxyInfo::calculate_size() const {
   uint32_t size = 0;
   size += ProtoSize::calc_length(1, this->name.size());
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->port_type));
+  size += this->port_type ? 2 : 0;
   return size;
 }
 #endif
@@ -232,7 +232,7 @@ uint32_t ListEntitiesBinarySensorResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -289,7 +289,7 @@ uint32_t ListEntitiesCoverResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_bool(1, this->supports_stop);
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -310,7 +310,7 @@ uint32_t CoverStateResponse::calculate_size() const {
   size += 5;
   size += ProtoSize::calc_float(1, this->position);
   size += ProtoSize::calc_float(1, this->tilt);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->current_operation));
+  size += this->current_operation ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -388,7 +388,7 @@ uint32_t ListEntitiesFanResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   if (!this->supported_preset_modes->empty()) {
     for (const char *it : *this->supported_preset_modes) {
       size += ProtoSize::calc_length_force(1, strlen(it));
@@ -415,7 +415,7 @@ uint32_t FanStateResponse::calculate_size() const {
   size += 5;
   size += ProtoSize::calc_bool(1, this->state);
   size += ProtoSize::calc_bool(1, this->oscillating);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->direction));
+  size += this->direction ? 2 : 0;
   size += ProtoSize::calc_int32(1, this->speed_level);
   size += ProtoSize::calc_length(1, this->preset_mode.size());
 #ifdef USE_DEVICES
@@ -512,9 +512,7 @@ uint32_t ListEntitiesLightResponse::calculate_size() const {
   size += 5;
   size += 2 + this->name.size();
   if (!this->supported_color_modes->empty()) {
-    for (const auto &it : *this->supported_color_modes) {
-      size += ProtoSize::calc_uint32_force(1, static_cast<uint32_t>(it));
-    }
+    size += this->supported_color_modes->size() * 2;
   }
   size += ProtoSize::calc_float(1, this->min_mireds);
   size += ProtoSize::calc_float(1, this->max_mireds);
@@ -527,7 +525,7 @@ uint32_t ListEntitiesLightResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(2, this->device_id);
 #endif
@@ -556,7 +554,7 @@ uint32_t LightStateResponse::calculate_size() const {
   size += 5;
   size += ProtoSize::calc_bool(1, this->state);
   size += ProtoSize::calc_float(1, this->brightness);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->color_mode));
+  size += this->color_mode ? 2 : 0;
   size += ProtoSize::calc_float(1, this->color_brightness);
   size += ProtoSize::calc_float(1, this->red);
   size += ProtoSize::calc_float(1, this->green);
@@ -711,9 +709,9 @@ uint32_t ListEntitiesSensorResponse::calculate_size() const {
   size += ProtoSize::calc_int32(1, this->accuracy_decimals);
   size += ProtoSize::calc_bool(1, this->force_update);
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->state_class));
+  size += this->state_class ? 2 : 0;
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -764,7 +762,7 @@ uint32_t ListEntitiesSwitchResponse::calculate_size() const {
 #endif
   size += ProtoSize::calc_bool(1, this->assumed_state);
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -837,7 +835,7 @@ uint32_t ListEntitiesTextSensorResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -882,7 +880,7 @@ void SubscribeLogsResponse::encode(ProtoWriteBuffer &buffer) const {
 }
 uint32_t SubscribeLogsResponse::calculate_size() const {
   uint32_t size = 0;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->level));
+  size += this->level ? 2 : 0;
   size += ProtoSize::calc_length(1, this->message_len_);
   return size;
 }
@@ -1115,7 +1113,7 @@ void ListEntitiesServicesArgument::encode(ProtoWriteBuffer &buffer) const {
 uint32_t ListEntitiesServicesArgument::calculate_size() const {
   uint32_t size = 0;
   size += ProtoSize::calc_length(1, this->name.size());
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->type));
+  size += this->type ? 2 : 0;
   return size;
 }
 void ListEntitiesServicesResponse::encode(ProtoWriteBuffer &buffer) const {
@@ -1135,7 +1133,7 @@ uint32_t ListEntitiesServicesResponse::calculate_size() const {
       size += ProtoSize::calc_message_force(1, it.calculate_size());
     }
   }
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->supports_response));
+  size += this->supports_response ? 2 : 0;
   return size;
 }
 bool ExecuteServiceArgument::decode_varint(uint32_t field_id, proto_varint_value_t value) {
@@ -1285,7 +1283,7 @@ uint32_t ListEntitiesCameraResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -1375,23 +1373,17 @@ uint32_t ListEntitiesClimateResponse::calculate_size() const {
   size += ProtoSize::calc_bool(1, this->supports_current_temperature);
   size += ProtoSize::calc_bool(1, this->supports_two_point_target_temperature);
   if (!this->supported_modes->empty()) {
-    for (const auto &it : *this->supported_modes) {
-      size += ProtoSize::calc_uint32_force(1, static_cast<uint32_t>(it));
-    }
+    size += this->supported_modes->size() * 2;
   }
   size += ProtoSize::calc_float(1, this->visual_min_temperature);
   size += ProtoSize::calc_float(1, this->visual_max_temperature);
   size += ProtoSize::calc_float(1, this->visual_target_temperature_step);
   size += ProtoSize::calc_bool(1, this->supports_action);
   if (!this->supported_fan_modes->empty()) {
-    for (const auto &it : *this->supported_fan_modes) {
-      size += ProtoSize::calc_uint32_force(1, static_cast<uint32_t>(it));
-    }
+    size += this->supported_fan_modes->size() * 2;
   }
   if (!this->supported_swing_modes->empty()) {
-    for (const auto &it : *this->supported_swing_modes) {
-      size += ProtoSize::calc_uint32_force(1, static_cast<uint32_t>(it));
-    }
+    size += this->supported_swing_modes->size() * 2;
   }
   if (!this->supported_custom_fan_modes->empty()) {
     for (const char *it : *this->supported_custom_fan_modes) {
@@ -1399,9 +1391,7 @@ uint32_t ListEntitiesClimateResponse::calculate_size() const {
     }
   }
   if (!this->supported_presets->empty()) {
-    for (const auto &it : *this->supported_presets) {
-      size += ProtoSize::calc_uint32_force(2, static_cast<uint32_t>(it));
-    }
+    size += this->supported_presets->size() * 3;
   }
   if (!this->supported_custom_presets->empty()) {
     for (const char *it : *this->supported_custom_presets) {
@@ -1412,7 +1402,7 @@ uint32_t ListEntitiesClimateResponse::calculate_size() const {
 #ifdef USE_ENTITY_ICON
   size += !this->icon.empty() ? 3 + this->icon.size() : 0;
 #endif
-  size += ProtoSize::calc_uint32(2, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 3 : 0;
   size += ProtoSize::calc_float(2, this->visual_current_temperature_step);
   size += ProtoSize::calc_bool(2, this->supports_current_humidity);
   size += ProtoSize::calc_bool(2, this->supports_target_humidity);
@@ -1446,16 +1436,16 @@ void ClimateStateResponse::encode(ProtoWriteBuffer &buffer) const {
 uint32_t ClimateStateResponse::calculate_size() const {
   uint32_t size = 0;
   size += 5;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->mode));
+  size += this->mode ? 2 : 0;
   size += ProtoSize::calc_float(1, this->current_temperature);
   size += ProtoSize::calc_float(1, this->target_temperature);
   size += ProtoSize::calc_float(1, this->target_temperature_low);
   size += ProtoSize::calc_float(1, this->target_temperature_high);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->action));
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->fan_mode));
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->swing_mode));
+  size += this->action ? 2 : 0;
+  size += this->fan_mode ? 2 : 0;
+  size += this->swing_mode ? 2 : 0;
   size += ProtoSize::calc_length(1, this->custom_fan_mode.size());
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->preset));
+  size += this->preset ? 2 : 0;
   size += ProtoSize::calc_length(1, this->custom_preset.size());
   size += ProtoSize::calc_float(1, this->current_humidity);
   size += ProtoSize::calc_float(1, this->target_humidity);
@@ -1586,7 +1576,7 @@ uint32_t ListEntitiesWaterHeaterResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -1594,9 +1584,7 @@ uint32_t ListEntitiesWaterHeaterResponse::calculate_size() const {
   size += ProtoSize::calc_float(1, this->max_temperature);
   size += ProtoSize::calc_float(1, this->target_temperature_step);
   if (!this->supported_modes->empty()) {
-    for (const auto &it : *this->supported_modes) {
-      size += ProtoSize::calc_uint32_force(1, static_cast<uint32_t>(it));
-    }
+    size += this->supported_modes->size() * 2;
   }
   size += ProtoSize::calc_uint32(1, this->supported_features);
   return size;
@@ -1618,7 +1606,7 @@ uint32_t WaterHeaterStateResponse::calculate_size() const {
   size += 5;
   size += ProtoSize::calc_float(1, this->current_temperature);
   size += ProtoSize::calc_float(1, this->target_temperature);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->mode));
+  size += this->mode ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -1700,9 +1688,9 @@ uint32_t ListEntitiesNumberResponse::calculate_size() const {
   size += ProtoSize::calc_float(1, this->max_value);
   size += ProtoSize::calc_float(1, this->step);
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_length(1, this->unit_of_measurement.size());
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->mode));
+  size += this->mode ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -1784,7 +1772,7 @@ uint32_t ListEntitiesSelectResponse::calculate_size() const {
     }
   }
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -1877,7 +1865,7 @@ uint32_t ListEntitiesSirenResponse::calculate_size() const {
   }
   size += ProtoSize::calc_bool(1, this->supports_duration);
   size += ProtoSize::calc_bool(1, this->supports_volume);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -1981,7 +1969,7 @@ uint32_t ListEntitiesLockResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_bool(1, this->assumed_state);
   size += ProtoSize::calc_bool(1, this->supports_open);
   size += ProtoSize::calc_bool(1, this->requires_code);
@@ -2001,7 +1989,7 @@ void LockStateResponse::encode(ProtoWriteBuffer &buffer) const {
 uint32_t LockStateResponse::calculate_size() const {
   uint32_t size = 0;
   size += 5;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->state));
+  size += this->state ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -2071,7 +2059,7 @@ uint32_t ListEntitiesButtonResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -2114,7 +2102,7 @@ uint32_t MediaPlayerSupportedFormat::calculate_size() const {
   size += ProtoSize::calc_length(1, this->format.size());
   size += ProtoSize::calc_uint32(1, this->sample_rate);
   size += ProtoSize::calc_uint32(1, this->num_channels);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->purpose));
+  size += this->purpose ? 2 : 0;
   size += ProtoSize::calc_uint32(1, this->sample_bytes);
   return size;
 }
@@ -2145,7 +2133,7 @@ uint32_t ListEntitiesMediaPlayerResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_bool(1, this->supports_pause);
   if (!this->supported_formats.empty()) {
     for (const auto &it : this->supported_formats) {
@@ -2170,7 +2158,7 @@ void MediaPlayerStateResponse::encode(ProtoWriteBuffer &buffer) const {
 uint32_t MediaPlayerStateResponse::calculate_size() const {
   uint32_t size = 0;
   size += 5;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->state));
+  size += this->state ? 2 : 0;
   size += ProtoSize::calc_float(1, this->volume);
   size += ProtoSize::calc_bool(1, this->muted);
 #ifdef USE_DEVICES
@@ -2627,9 +2615,9 @@ void BluetoothScannerStateResponse::encode(ProtoWriteBuffer &buffer) const {
 }
 uint32_t BluetoothScannerStateResponse::calculate_size() const {
   uint32_t size = 0;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->state));
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->mode));
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->configured_mode));
+  size += this->state ? 2 : 0;
+  size += this->mode ? 2 : 0;
+  size += this->configured_mode ? 2 : 0;
   return size;
 }
 bool BluetoothScannerSetModeRequest::decode_varint(uint32_t field_id, proto_varint_value_t value) {
@@ -2965,7 +2953,7 @@ uint32_t ListEntitiesAlarmControlPanelResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_uint32(1, this->supported_features);
   size += ProtoSize::calc_bool(1, this->requires_code);
   size += ProtoSize::calc_bool(1, this->requires_code_to_arm);
@@ -2984,7 +2972,7 @@ void AlarmControlPanelStateResponse::encode(ProtoWriteBuffer &buffer) const {
 uint32_t AlarmControlPanelStateResponse::calculate_size() const {
   uint32_t size = 0;
   size += 5;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->state));
+  size += this->state ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3054,11 +3042,11 @@ uint32_t ListEntitiesTextResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += ProtoSize::calc_uint32(1, this->min_length);
   size += ProtoSize::calc_uint32(1, this->max_length);
   size += ProtoSize::calc_length(1, this->pattern.size());
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->mode));
+  size += this->mode ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3139,7 +3127,7 @@ uint32_t ListEntitiesDateResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3222,7 +3210,7 @@ uint32_t ListEntitiesTimeResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3309,7 +3297,7 @@ uint32_t ListEntitiesEventResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
   if (!this->event_types->empty()) {
     for (const char *it : *this->event_types) {
@@ -3365,7 +3353,7 @@ uint32_t ListEntitiesValveResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
   size += ProtoSize::calc_bool(1, this->assumed_state);
   size += ProtoSize::calc_bool(1, this->supports_position);
@@ -3387,7 +3375,7 @@ uint32_t ValveStateResponse::calculate_size() const {
   uint32_t size = 0;
   size += 5;
   size += ProtoSize::calc_float(1, this->position);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->current_operation));
+  size += this->current_operation ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3448,7 +3436,7 @@ uint32_t ListEntitiesDateTimeResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3522,7 +3510,7 @@ uint32_t ListEntitiesUpdateResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
   size += !this->device_class.empty() ? 2 + this->device_class.size() : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
@@ -3634,7 +3622,7 @@ void ZWaveProxyRequest::encode(ProtoWriteBuffer &buffer) const {
 }
 uint32_t ZWaveProxyRequest::calculate_size() const {
   uint32_t size = 0;
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->type));
+  size += this->type ? 2 : 0;
   size += ProtoSize::calc_length(1, this->data_len);
   return size;
 }
@@ -3664,7 +3652,7 @@ uint32_t ListEntitiesInfraredResponse::calculate_size() const {
   size += !this->icon.empty() ? 2 + this->icon.size() : 0;
 #endif
   size += ProtoSize::calc_bool(1, this->disabled_by_default);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->entity_category));
+  size += this->entity_category ? 2 : 0;
 #ifdef USE_DEVICES
   size += ProtoSize::calc_uint32(1, this->device_id);
 #endif
@@ -3851,8 +3839,8 @@ void SerialProxyRequestResponse::encode(ProtoWriteBuffer &buffer) const {
 uint32_t SerialProxyRequestResponse::calculate_size() const {
   uint32_t size = 0;
   size += ProtoSize::calc_uint32(1, this->instance);
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->type));
-  size += ProtoSize::calc_uint32(1, static_cast<uint32_t>(this->status));
+  size += this->type ? 2 : 0;
+  size += this->status ? 2 : 0;
   size += ProtoSize::calc_length(1, this->error_message.size());
   return size;
 }
diff --git a/script/api_protobuf/api_protobuf.py b/script/api_protobuf/api_protobuf.py
index 260c696dc0..7b0e81af4e 100755
--- a/script/api_protobuf/api_protobuf.py
+++ b/script/api_protobuf/api_protobuf.py
@@ -56,6 +56,10 @@ FILE_HEADER = """// This file was automatically generated with a tool.
 // See script/api_protobuf/api_protobuf.py
 """
 
+# Populated by main() before any TypeInfo creation.
+# Maps enum type name (e.g. ".BluetoothDeviceRequestType") to max enum value.
+_enum_max_values: dict[str, int] = {}
+
 
 def indent_list(text: str, padding: str = "  ") -> list[str]:
     """Indent each line of the given text with the specified padding."""
@@ -1338,6 +1342,14 @@ class EnumType(TypeInfo):
     default_value = ""
     wire_type = WireType.VARINT  # Uses wire type 0
 
+    @property
+    def max_value(self) -> int | None:
+        """Get max_value from explicit annotation or auto-derive from enum definition."""
+        explicit = super().max_value
+        if explicit is not None:
+            return explicit
+        return _enum_max_values.get(self._field.type_name)
+
     @property
     def encode_func(self) -> str:
         return "encode_uint32"
@@ -1360,6 +1372,9 @@ class EnumType(TypeInfo):
         return f"static_cast<{self.cpp_type}>({value})"
 
     def get_size_calculation(self, name: str, force: bool = False) -> str:
+        max_val = self.max_value
+        if max_val is not None and max_val < 128:
+            return self._get_single_byte_varint_size(name, force)
         return self._get_simple_size_calculation(
             name, force, "uint32", f"static_cast<uint32_t>({name})"
         )
@@ -1918,17 +1933,27 @@ class RepeatedTypeInfo(TypeInfo):
             size_expr = f"{name}->size()" if self._use_pointer else f"{name}.size()"
             o += f"  size += {size_expr} * {bytes_per_element};\n"
         else:
-            # Other types need the actual value
+            # Check if inner type produces a constant size (doesn't depend on value)
+            inner_size = self._ti.get_size_calculation("it", True)
+            if "it" not in inner_size:
+                # Constant size per element — use multiply instead of loop
+                # Extract the constant from "size += N;"
+                const_val = (
+                    inner_size.strip().removeprefix("size += ").removesuffix(";")
+                )
+                size_expr = f"{name}->size()" if self._use_pointer else f"{name}.size()"
+                o += f"  size += {size_expr} * {const_val};\n"
             # Special handling for const char* elements
-            if self._use_pointer and "const char" in self._container_no_template:
+            elif self._use_pointer and "const char" in self._container_no_template:
                 field_id_size = self.calculate_field_id_size()
                 o += f"  for (const char *it : {container_ref}) {{\n"
                 o += f"    size += ProtoSize::calc_length_force({field_id_size}, strlen(it));\n"
+                o += "  }\n"
             else:
                 auto_ref = "" if self._ti_is_bool else "&"
                 o += f"  for (const auto {auto_ref}it : {container_ref}) {{\n"
-                o += f"    {self._ti.get_size_calculation('it', True)}\n"
-            o += "  }\n"
+                o += f"    {inner_size}\n"
+                o += "  }\n"
 
         o += "}"
         return o
@@ -2797,6 +2822,11 @@ def main() -> None:
 
     file = d.file[0]
 
+    # Build enum max value map so EnumType can auto-derive max_value
+    for enum in file.enum_type:
+        if not enum.options.deprecated and enum.value:
+            _enum_max_values[f".{enum.name}"] = max(v.number for v in enum.value)
+
     # Build dynamic ifdef mappings early so we can emit USE_API_VARINT64 before includes
     enum_ifdef_map, message_ifdef_map, message_source_map, used_messages = (
         build_type_usage_map(file)