Got the GE Cync dimmer w/ motion sensor for the garage and as a standalone, works well. Works too within Google Home as well. The one I refer to is here (motion+dimming).
So my questions in regards to SmartThings:
1- Is there a way to make ST see what is in GH and use it? I read about virtual switches but looking for simpler if available, was naively expecting devices from one to another to be visible. I know Matter is supposed to solve this but alas here we are.
2- In regards to the motion sensor, has anyone tried to use it in GH and/or ST?
Disappointing GE did not do an integration/certification with ST really.
Motion sensors can’t trigger Google Home Routines, so there is no way to bring it into ST using GH.
If you can get it into the Alexa app (no device needed) you could use it to trigger a virtual motion sensor (created in ST) using an Alexa routine. And that would be your link to ST.