finally got sonoff dual r1 code esphome working as I need

esphome/esp-mainbathfancombo.yaml

@@ -17,19 +17,34 @@
 # If NOT using a secrets file, just replace these with the passwords etc (in quotes)
 #############################################
 substitutions:
+  # Device Naming
   device_name: "esp-mainbathfancombo"
-  project_name: "Zemismart Technologies.KS-811-2 (Double)" # Project Details 
-  project_version: "v1"  # Project V denotes release of yaml file, allowing checking of deployed vs latest version
-  entity_prefix: "Main Bathroom" # Simple device name where we want to prefix a sensor or switch, eg "Load" Current. 
   friendly_name: "Main Bathroom Fan/Heat Combo Switch (2)"
   description_comment: "Main Bathroom Fan/Heat Switch using a Zemismart KS-811 Double Push Button. Extract Fan (1), IR heater (2)"
   device_area: "Laundry" # Allows ESP device to be automatically linked to an 'Area' in Home Assistant.  
+  
+   # Project Naming
+  project_name: "Zemismart Technologies.KS-811-2 (Double)" # Project Details 
+  project_version: "v1"  # Project V denotes release of yaml file, allowing checking of deployed vs latest version
+  
+  entity_prefix: "Main Bathroom" # Simple device name where we want to prefix a sensor or switch, eg "Load" Current. 
+
+  # Passwords
   api_key: !secret esp-api_key # unfortunately you can't use substitutions inside secrets names
   ota_pass: !secret esp-ota_pass # unfortunately you can't use substitutions inside secrets names
   static_ip_address: !secret esp-mainbathfancombo_ip
+  
+  # Device Settings
+  #relay_icon: "mdi:heating-coil"
   log_level: "INFO" # Define logging level: NONE, ERROR, WARN, INFO, DEBUG (Default), VERBOSE, VERY_VERBOSE
   update_interval: "60s" # update time for for general sensors etc
 
+  # MQTT Controls
+  mqtt_main_command_topic: !secret mqtt_main_command_topic
+  #mqtt_main_status_topic: !secret mqtt_main_status_topic
+  mqtt_remote_device1_command_topic: "${mqtt_main_command_topic}/masterbath-towelrail/operation"
+  mqtt_remote_device1_command1: "BOOST"
+
 #############################################
 # Included Common Packages
 # https://esphome.io/components/esphome.html
@@ -71,6 +86,12 @@ esphome:
   project:
     name: "${project_name}"
     version: "${project_version}"
+  platformio_options:
+    build_flags:
+      - "-Os"                   # optimize for size
+      - "-Wl,--gc-sections"     # drop unused code/data
+      - "-fno-exceptions"       # strip C++ exceptions
+      - "-fno-rtti"             # strip C++ RTTI
 #  on_boot:       
 #    priority: 200
 #    then:
@@ -90,7 +111,7 @@ esp8266:
 # https://esphome.io/components/logger.html
 ############################################# 
 logger:
-  level: ${log_level}  #INFO Level suggested, or DEBUG for testing
+  level: "${log_level}"  #INFO Level suggested, or DEBUG for testing
   #baud_rate: 0 #set to 0 for no logging via UART, needed if you are using it for other serial things (eg PZEM)
   #esp8266_store_log_strings_in_flash: false
   #tx_buffer_size: 64
@@ -99,6 +120,8 @@ logger:
 # STATUS LED
 # https://esphome.io/components/status_led.html
 #############################################
+# Status LED for KS-811 is gpio2
+#############################################
 status_led:
   pin:
     number: GPIO2
@@ -108,6 +131,8 @@ status_led:
 # BINARY SENSORS
 # https://esphome.io/components/binary_sensor/
 #############################################
+# Buttons for KS-811-2 are GPIO16, GPIO05
+#############################################
 binary_sensor:
   - platform: gpio
     pin:
@@ -116,21 +141,43 @@ binary_sensor:
       inverted: True
     name: "Button 1: Extract Fan"
     on_press:
-      - switch.toggle: Relay_1
+      - switch.toggle: "Relay_1"
 
   - platform: gpio
     pin:
       number: GPIO05
       mode: INPUT
-      inverted: True
+      inverted: true
     name: "Button 2: IR Heater"
-    on_press:
-      - switch.toggle: Relay_2
+    filters:
+      - delayed_on: 20ms
+      - delayed_off: 20ms
+
+    on_multi_click:
+      # ── Single click: one quick press & release ─────────────────
+      - timing:
+          - ON for at most 400ms
+          - OFF for at least 200ms
+        then:
+          - switch.toggle: "Relay_2"
+
+      # ── Double click: two quick presses/releases ───────────────
+      - timing:
+          - ON for at most 400ms
+          - OFF for at most 400ms
+          - ON for at most 400ms
+          - OFF for at least 200ms
+        then:
+          - mqtt.publish:
+              topic: "${mqtt_remote_device1_command_topic}"
+              payload: "${mqtt_remote_device1_command1}"
 
 #############################################
 # SWITCH COMPONENT
 # https://esphome.io/components/switch/
 #############################################
+# Relays for KS-811-2 are GPIO13, GPIO12
+#############################################
 switch:
   - platform: gpio
     name: "Relay 1: Extract Fan"
@@ -141,6 +188,8 @@ switch:
     name: "Relay 2: IR Heater"
     pin: GPIO12
     id: Relay_2
+    # Always run the fan when IR heater on.  Not critical for this heat/lamp product
+    # as it has its own failsafes and fan switching on temp, but an added safety measure
     on_turn_on:
-      switch.turn_on: Relay_1
+      switch.turn_on: "Relay_1"