My French registered Robin is based here in UK and I have a contract with a British CAMO. He can renew the ARC and issue CRS if required. Main difference is the ARC renewal notification is sent to GSAC France rather than CAA SRG in UK. One very big advantage is that most EU member states use the aircraft manufacturer's type specific maintenance program. This makes owner maintenance easy(see part M Appendix VIII pilot/owner maintenance) Unlike the British LAMP which is a generic program which has to be interpreted by engineers to do as much or as little work as they choose. Stay on your present register, but be prepared to shop around till you find a maintenance organisation that you can trust.