diff --git a/esphome/components/api/api_connection.cpp b/esphome/components/api/api_connection.cpp
index 6fb0542081..e0372b6cd4 100644
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -1898,13 +1898,13 @@ void APIConnection::process_batch_() {
 
 uint16_t APIConnection::MessageCreator::operator()(EntityBase *entity, APIConnection *conn, uint32_t remaining_size,
                                                    bool is_single, uint16_t message_type) const {
-  if (is_string()) {
+  if (has_tagged_string_ptr_()) {
     // Handle string-based messages
     switch (message_type) {
 #ifdef USE_EVENT
       case EventResponse::MESSAGE_TYPE: {
         auto *e = static_cast<event::Event *>(entity);
-        return APIConnection::try_send_event_response(e, *get_string_ptr(), conn, remaining_size, is_single);
+        return APIConnection::try_send_event_response(e, *get_string_ptr_(), conn, remaining_size, is_single);
       }
 #endif
       default:
diff --git a/esphome/components/api/api_connection.h b/esphome/components/api/api_connection.h
index a25aa8012e..f983a0483b 100644
--- a/esphome/components/api/api_connection.h
+++ b/esphome/components/api/api_connection.h
@@ -486,6 +486,9 @@ class APIConnection : public APIServerConnection {
 
   // Optimized MessageCreator class using tagged pointer
   class MessageCreator {
+    // Ensure pointer alignment allows LSB tagging
+    static_assert(alignof(std::string *) > 1, "String pointer alignment must be > 1 for LSB tagging");
+
    public:
     // Constructor for function pointer
     MessageCreator(MessageCreatorPtr ptr) {
@@ -503,15 +506,15 @@ class APIConnection : public APIServerConnection {
 
     // Destructor
     ~MessageCreator() {
-      if (is_string()) {
-        delete get_string_ptr();
+      if (has_tagged_string_ptr_()) {
+        delete get_string_ptr_();
       }
     }
 
     // Copy constructor
     MessageCreator(const MessageCreator &other) {
-      if (other.is_string()) {
-        auto *str = new std::string(*other.get_string_ptr());
+      if (other.has_tagged_string_ptr_()) {
+        auto *str = new std::string(*other.get_string_ptr_());
         data_.tagged = reinterpret_cast<uintptr_t>(str) | 1;
       } else {
         data_ = other.data_;
@@ -525,12 +528,12 @@ class APIConnection : public APIServerConnection {
     MessageCreator &operator=(const MessageCreator &other) {
       if (this != &other) {
         // Clean up current string data if needed
-        if (is_string()) {
-          delete get_string_ptr();
+        if (has_tagged_string_ptr_()) {
+          delete get_string_ptr_();
         }
         // Copy new data
-        if (other.is_string()) {
-          auto *str = new std::string(*other.get_string_ptr());
+        if (other.has_tagged_string_ptr_()) {
+          auto *str = new std::string(*other.get_string_ptr_());
           data_.tagged = reinterpret_cast<uintptr_t>(str) | 1;
         } else {
           data_ = other.data_;
@@ -542,8 +545,8 @@ class APIConnection : public APIServerConnection {
     MessageCreator &operator=(MessageCreator &&other) noexcept {
       if (this != &other) {
         // Clean up current string data if needed
-        if (is_string()) {
-          delete get_string_ptr();
+        if (has_tagged_string_ptr_()) {
+          delete get_string_ptr_();
         }
         // Move data
         data_ = other.data_;
@@ -559,10 +562,13 @@ class APIConnection : public APIServerConnection {
 
    private:
     // Check if this contains a string pointer
-    bool is_string() const { return (data_.tagged & 1) != 0; }
+    bool has_tagged_string_ptr_() const { return (data_.tagged & 1) != 0; }
 
     // Get the actual string pointer (clears the tag bit)
-    std::string *get_string_ptr() const { return reinterpret_cast<std::string *>(data_.tagged & ~uintptr_t(1)); }
+    std::string *get_string_ptr_() const {
+      // NOLINTNEXTLINE(performance-no-int-to-ptr)
+      return reinterpret_cast<std::string *>(data_.tagged & ~uintptr_t(1));
+    }
 
     union {
       MessageCreatorPtr ptr;
diff --git a/esphome/core/automation.h b/esphome/core/automation.h
index 02c9d44f16..e156818312 100644
--- a/esphome/core/automation.h
+++ b/esphome/core/automation.h
@@ -27,20 +27,67 @@ template<typename T, typename... X> class TemplatableValue {
  public:
   TemplatableValue() : type_(NONE) {}
 
-  template<typename F, enable_if_t<!is_invocable<F, X...>::value, int> = 0>
-  TemplatableValue(F value) : type_(VALUE), value_(std::move(value)) {}
+  template<typename F, enable_if_t<!is_invocable<F, X...>::value, int> = 0> TemplatableValue(F value) : type_(VALUE) {
+    new (&this->value_) T(std::move(value));
+  }
 
-  template<typename F, enable_if_t<is_invocable<F, X...>::value, int> = 0>
-  TemplatableValue(F f) : type_(LAMBDA), f_(f) {}
+  template<typename F, enable_if_t<is_invocable<F, X...>::value, int> = 0> TemplatableValue(F f) : type_(LAMBDA) {
+    this->f_ = new std::function<T(X...)>(std::move(f));
+  }
+
+  // Copy constructor
+  TemplatableValue(const TemplatableValue &other) : type_(other.type_) {
+    if (type_ == VALUE) {
+      new (&this->value_) T(other.value_);
+    } else if (type_ == LAMBDA) {
+      this->f_ = new std::function<T(X...)>(*other.f_);
+    }
+  }
+
+  // Move constructor
+  TemplatableValue(TemplatableValue &&other) noexcept : type_(other.type_) {
+    if (type_ == VALUE) {
+      new (&this->value_) T(std::move(other.value_));
+    } else if (type_ == LAMBDA) {
+      this->f_ = other.f_;
+      other.f_ = nullptr;
+    }
+    other.type_ = NONE;
+  }
+
+  // Assignment operators
+  TemplatableValue &operator=(const TemplatableValue &other) {
+    if (this != &other) {
+      this->~TemplatableValue();
+      new (this) TemplatableValue(other);
+    }
+    return *this;
+  }
+
+  TemplatableValue &operator=(TemplatableValue &&other) noexcept {
+    if (this != &other) {
+      this->~TemplatableValue();
+      new (this) TemplatableValue(std::move(other));
+    }
+    return *this;
+  }
+
+  ~TemplatableValue() {
+    if (type_ == VALUE) {
+      this->value_.~T();
+    } else if (type_ == LAMBDA) {
+      delete this->f_;
+    }
+  }
 
   bool has_value() { return this->type_ != NONE; }
 
   T value(X... x) {
     if (this->type_ == LAMBDA) {
-      return this->f_(x...);
+      return (*this->f_)(x...);
     }
     // return value also when none
-    return this->value_;
+    return this->type_ == VALUE ? this->value_ : T{};
   }
 
   optional<T> optional_value(X... x) {
@@ -58,14 +105,16 @@ template<typename T, typename... X> class TemplatableValue {
   }
 
  protected:
-  enum {
+  enum : uint8_t {
     NONE,
     VALUE,
     LAMBDA,
   } type_;
 
-  T value_{};
-  std::function<T(X...)> f_{};
+  union {
+    T value_;
+    std::function<T(X...)> *f_;
+  };
 };
 
 /** Base class for all automation conditions.
diff --git a/esphome/core/component_iterator.cpp b/esphome/core/component_iterator.cpp
index da593340c1..03c8fb44f9 100644
--- a/esphome/core/component_iterator.cpp
+++ b/esphome/core/component_iterator.cpp
@@ -375,7 +375,7 @@ void ComponentIterator::advance() {
   }
 
   if (advance_platform) {
-    this->state_ = static_cast<IteratorState>(static_cast<uint32_t>(this->state_) + 1);
+    this->state_ = static_cast<IteratorState>(static_cast<uint16_t>(this->state_) + 1);
     this->at_ = 0;
   } else if (success) {
     this->at_++;
diff --git a/esphome/core/component_iterator.h b/esphome/core/component_iterator.h
index 9e187f6c57..4b41872db7 100644
--- a/esphome/core/component_iterator.h
+++ b/esphome/core/component_iterator.h
@@ -93,7 +93,9 @@ class ComponentIterator {
   virtual bool on_end();
 
  protected:
-  enum class IteratorState {
+  // Iterates over all ESPHome entities (sensors, switches, lights, etc.)
+  // Supports up to 256 entity types and up to 65,535 entities of each type
+  enum class IteratorState : uint8_t {
     NONE = 0,
     BEGIN,
 #ifdef USE_BINARY_SENSOR
@@ -167,7 +169,7 @@ class ComponentIterator {
 #endif
     MAX,
   } state_{IteratorState::NONE};
-  size_t at_{0};
+  uint16_t at_{0};  // Supports up to 65,535 entities per type
   bool include_internal_{false};
 };