This is exactly why I’ve started only buying smart devices that work with Home Assistant and don’t rely on cloud services.
And is actively trying to prevent hackers from running stuff locally.
Then they couldn't resist fiddling with the UI. Every new update changed the UI such that I had to relearn how to operate it.
That was the last straw, so I disconnected it from my wifi and just used it as a standalone thermostat.
Curious to hear what local polling or local push thermostat you settled on with HA support!
A shortcut however is checking out the homelab subreddit. People will post about the gear they are using in their stack.
* There are internet-connected controllers and local controllers so you'd also want a local controller. I've used an Aeotec Z-Stick for ZWave devices for around a decade, it plugs into USB, HomeAssistant accesses it directly, and the ZWave network itself is connections between the Z-Stick and the devices without the internet.
Source: I own one. :)