Even if we walk, as harry says, the issue of licenses is almost moot as EASA Approved organisations should simply convert to 'Foreign' status and Licences would remain as they are - and continue to remain valid for renewal at your chosen EASA state. This situation should be the same for anyone holding FAA, CASA, NZCAA, etc, licences.
The CAA would HAVE TO issue 'Grandfather Rights' (again) licences to all currently licensed engineers and also issue BCAR Approvals to all current companies. The same as happened when joining JAA/EASA. (the same for pilots licences too)
The ONLY argument in the papers seems to be about travelling rights and I believe that is adequately covered by ICAO rules for freedom of international movement and access to destinations/airways.
Again, in my opinion, there is only complication for everyone in the perceived split - but there is no advantage for anyone mandating it. (edited bit
there will be fees, of course!