During takeoff I will use ASS until 1,000m and then switch to the aircraft autopilot, however right now I have to turn off ASS first before I can enable AP. It would be nice if pressing a button to activate AP automatically turn off ASS.

Along those lines I would find it helpful to default to ASS when turning off aircraft AP or landing guidance, so when you deactivate them whatever you have set for ASS can keep control so you stay horizontal, or for landing guidance, surface up.