Disable save state on flash

Disable save power state

SetOption0 0

Save flash write count. since state save on MQTT server, we not need write to flash.
SetOption0 Save power state and use after restart (=SaveState)
0 = disable (see note below)
1 = enable (default)
https://tasmota.github.io/docs/Commands/#setoptions

Set power on state

PowerOnState 0

Default power on state, since state is not save on flash.
PowerOnState Control relay state after powering up the device.
0 / OFF = keep relay(s) OFF after power up
1 / ON = turn relay(s) ON after power up
2 / TOGGLE = toggle relay(s) from last saved state
3 = switch relay(s) to their last saved state (default)
4 = turn relay(s) ON and disable further relay control
5 = after a PulseTime period turn relay(s) ON (acts as inverted PulseTime mode)
https://tasmota.github.io/docs/PowerOnState/

Tasmota rule for save state on MQTT

State Rule

Rule1
  ON Power1#state=0 DO publish2 cmnd/%topic%/POWER1 OFF ENDON
  ON Power1#state=1 DO publish2 cmnd/%topic%/POWER1 ON ENDON
  ON Power2#state=0 DO publish2 cmnd/%topic%/POWER2 OFF ENDON
  ON Power2#state=1 DO publish2 cmnd/%topic%/POWER2 ON ENDON
  ON Power3#state=0 DO publish2 cmnd/%topic%/POWER3 OFF ENDON
  ON Power3#state=1 DO publish2 cmnd/%topic%/POWER3 ON ENDON

Rule1 1

Echo current power state to MQTT with lastwill(save last message).
Use publish2 to publish MQTT command with lastwill.

Disable/Enable rule on system start up

Rule2
  ON System#Init DO Rule1 0 ENDON
  ON System#Boot DO Rule1 1 ENDON

Rule2 1

Disable rule1 on system init. so when system still start up, it will not send MQTT command with incorrect state.
Enable rule1 after system done start and already received MQTT command back.

System#Init occurs once after restart before Wi-Fi and MQTT are initialized
System#Boot occurs once after Tasmota is fully initialized, triggers after Wi-Fi and MQTT (if enabled) are connected.
https://tasmota.github.io/docs/Rules/#examples-of-available-triggers