I have two smart switches attached to lights (since our apartment has no overhead lighting) and after a nightmare of setting them up (probably the hardware's fault, but homekit couldn't recognize them via normal pairing method) they worked for a few months.

Randomly though they fail to work in Home and I have to manually reset them by holding in the button on the device and redo the entire process. This isn't workable at any scale (it's even annoying with just the two that I have).