I think you’re right about the plate with studs. On the other hand, I’m pretty sure a tile without studs can be put between studs like that and be legal.

I use the Home Assistant Cloud Remote Control feature, which gives an external URL essentially. It does run through Home Assistant’s servers for external access, but I don’t really mind. I was using a DIY DuckDNS setup, but decided to start using HA Cloud for the Google Assistant integration. Using Remote Control is really easy, and I don’t have to think about my setup.