Twiglet1, you appear to be talking almost entirely about long-haul. I have no desire to bring back Flight Engineers, I have never flown with one and the first model of the type that I fly was developed without flight engineers five decades ago (a few year before my career started).
Short-haul is not the same. EASA FTLs permit seven consecutive 'earlies' totalling 60 duty hours, one "extended recovery rest period", then do it all again. Not a 'perception', it is in black-and-white.
Yes, Working Time Directives will 'protect' against the worst of it and this can be by making use of a Pilot's leave to bring those duty hour averages down (i.e. you have the worst of the FTLs thrown at you just before your leave). But how often have crews heard the response to a query about a duty that "it's legal"?
Your experience that "most UK AOC's took a mature stance on EASA FTL" still implies that not all did.
Only a robust Scheduling Agreement or a good fixed-pattern roster are protection against EASA's 'Fatigue Target Limitations'. (I have the protection of an excellent fixed-pattern roster against long-term fatigue.)
wiggy's comment that BA Short Haul "went almost fully EASA" is a worry.