I currently use a Lemfo LEM16 as a daily driver because I have set it up for NFC payment. I have no problems with overheating and rapid discharge. But I also deleted many apps that I don’t need, such as the Assistant app, the Watchface Store, the Updater, the stock browser, the live wallpapers and many, many others.
I described how this works here:
-How to delete installed Apps on Android 10
The problem can be triggered by the Watch Face Store app, for example: If the Watchface server is down and the app tries to connect to this server.
Along the way I got a watch that fulfilled all my wishes and had reasonable battery consumption.