The EASA position is based around "reciprocity".
This seems fair enough - hard to argue with that. A bit like the Body Shop having a petition you can put your name to, requesting a stop of all torture. Or Bob Geldof doing a pop concert to stop poverty.
Unfortunately the principle is being applied over a wide spectrum of stuff and I don't think it will be resolved until it gets quite close to heads being banged together. But it will be resolved (it must be).
Partm M is a separate thing; the above would be relevant if one was for example hoping to get an automatic acceptance of FAA certification (like e.g. Australia does). But this is politically very hard. Think of how many thousands of EU careers have been invested in developing "European standards" for everything.
I think one of two things must happen on this, in the long term:
a) EASA will accept FAA FCL and certification more or less unchanged (OK it will be wrapped up in the usual EU symbolism), OR
b) No action will be taken against European based N-reg planes
I know (from the horse's mouth) that EASA knows perfectly well that if they implemented option a), the N-reg scene would dry up. Well everybody knows that!