No bother. Sonoff now have a ‘DIY’ mode so you can OTA flash something like ESPHome or Tasmota to make the integration with HA easier.
The one advantage some of these other relays have is that they offer a Normally Closed (NC or Normally Open (NO) option i.e. the relay defaults (no power to relay) open circuit or closed.
I’m putting a relay override on my mechanical tank thermostat so I can make the boiler heat the tank more or less depending on conditions. However, I’m using 2 relays one NC and one NO so if the relays lose power it reverts to the mechanical thermostat.
I’ve also set up my heating so I have not removed the ‘wall’ thermostat, just override it (relay is in parallel), so again, if the control system goes AWOL, it reverts to the wall themostat.
HTH