It works much better than previously.
The bug when pressing numerous times F12 (toggle menu bar) has disappeared.
I can toggle full screen / menu bar as many times as I want and frame dimensions
When I switch resolution between my laptop screen and an external monitor, things are also working
albeit numerous redisplays happen. The screen flickers quite a lot, but the result is ok.
I don't know if some of this flickering could be avoided or not.
Thanks for your work, it is much appreciated.