I put a Shelly 1PM in the switch box for the fan, it’s been operating for several months w/o issues. I intend to move it to the fan itself (so I’ll have independent control of the lights), but haven’t gotten around to it yet.
You’d need a snubber for a motor like a fan, don’t forget.
The docs seem to only reference use on lights; and the max output amp is 10. Ceiling fans typically draw less than 2 amps but can go up to 6; this circuit sends power to two fans; so, technically, they could try to pull 12 amps (although unlikely).
They are Hunter 52 inch fans; checked and the Hunter switches are rated for 1.6 amps - so, I’m relatively sure it’s fine; just wanted to see if anyone else had tried.