I use several Iris wall plugs, but I’m not sure where you’ll find them now. ST’s are also good. You can always replace wall switches with GE’s Zigbee wall switch. I have many of those, and they are really good devices.
It’s your account that was converted, but you can still use Classic for now. The new app and Classic are different, and have different built in apps like Smart Home Monitor, and others, so catch up here:
The new app is still very buggy, and they can now make changes in the background without letting you know, or sending you any notification of what’s changing. That’s actually going on right now with new features they added to devices that have rendered most of my devices useless in the new app.
I still use Classic, and try to use the new app; but it’s not going well.
EDIT: perfect example is right at this moment. I can’t open the new app without it crashing on my phone.