I also looking for replacement for my phone, and I want to use with AndroidAPS like you (android 8.1 or above required).
Few mounts ago I bought LEMFO LEM16, it’s powerful and have android 11, but apps almost always open in square inscribed in a circle,. So basically doing things on 1,6 circle display for me is ok, but on 1.6’’ square is painful. And protruding edges of the watch above the screen only make things worse.
After 2 days of tests I put watch back to box.
Maybe I will try one more time, but right now I looking for something with rectangular display as you.
I more go for lower energy ARM, and better battery management than more bulky battery. But at least 18 hours on AndroidAPS and companion apps (that constantly tigers BT) is must have. (AAPS do some small calculation every 5 min or sometimes 1min, depends what other devices you are using)
Reopened similar topic here,
before found this one. Already get some answers.