In addition Im planning virtual thermostats, which can watch temp sensors, and control local/remote devices, with auto updates to Home Assistant.

While Im writing this generally, it makes a great multi-zone radiant heat controller. (Im using it as a 8 zone heating system.

I've already got it talking to HomeAssistant, auto registering sensors, and sending updates, as well as controlling relays. All auto discovered. I've designed it for auto update as well over the network, and adding more configurabilility to it.

Just discovery your 10Amp relays with esp32, so plan to add support for them(By doing a mini version of the app).
And I saw your lcd driver, which could be used as a display. (Single grove port, so bigger switch would be useful.

I'd love to see a couple of things:

1. A TCA9548A based i2c switch with settable address. I already have support for multiple switches if you can set the address. This really would help on devices with less grove ports (Even 1 is good).
2. A 10 Amp Solid State Relay for 110-220VAC