I don't know about AEX internal updater as I did not tesr AEX too much. I stick with Arrow these days.
But reat should be same as they use same tree.
I don't see display brightness fluctuation issues here btw.
Many thanks @weimerd for the reference to ArrowOS.
I put it on phone this weekend and it runs so much smoother than ZUI and the internal updater works verifiable! Everything is working properly. The battery consumption is not unusual, without having measurements I would say no more than before.
I really was looking for a new phone for months, with fresh Android, updates and so on, but EXACTLY the one that really has everything I want - it doesn't exist. Good thing I searched for so long and stumbled across this thread here!
It feels like I had downloaded a new mobile for free from the net... That´s exactly my cup of tea.