The built in Google Home app is very limited to basic devices.
You will probably want to check this out: [Alpha] Community-maintained Google Home integration
Despite saying it is "Alpha" I would definitely consider it beta at least, it is pretty solid.
Its a little bit of work to set it up, but the instructions are very good, and once it is setup you wont have to mess with it again.
I would guess Z-Wave but once they are integrated to HE, it is not important for sharing to Google. A switch is a switch and a shade is a shade, HE will take care of communicating to them, Google will communicate with HE. I just think the GH system app does not support shades.
