Interesting that it is assumed that PFA/BMAA are responsible for the airworthiness regulation of aircraft.
The reality is that the CAA is responsible. PFA/BMAA are CAA Approved Organisations for the issue of Permits. One suspects that there is little to stop:-
a. Any other organisation going for a similar approval.
b. PFA or BMAA getting M3 approval if they decided that was what they wanted to do and looking after C of A renewals as well.
That would stir things up a bit !