Not OP, but the Shelly 1 works very well as a simple switch, and it supports both physical and remote operations. Not sure what you mean by "stateless", though

Not OP, but the Shelly 1 works very well as a simple switch, and it supports both physical and remote operations. Not sure what you mean by "stateless", though (I mean, the thing is either on or off?), so that might prevent you from using it, but otherwise it's highly recommended!