I know this was a year ago, but just seen the response.
I spent quite some time trying to get the rules based rain sensor functionality working at the time of the post, but never had any luck.
I’ve just had another look in the app now, and I’m fairly certain there’s actually new functionality allowing this form of automation. I don’t recall being able to set the state of the rain sensor previously.
Actually - I think I’m correct, as Inkbird did respond to this question to me but in another thread at the time:
So it’s nice to see this functionality is now there. I’m not using it however as I ended up just buying a rain sensor instead. But it’s useful to know for others…
Thanks