‘Principal place of business’ means the head office or registered office of the organisation within which the principal financial functions and operational control of the activities referred to in this Regulation are exercised.
That would surely be difficult to prove in a court of law. A European owned VP reg, N reg or M reg BizJet's owner could easily start a non European affiliate shelf company and operate the aircraft (paperwork wise) from that non-EU base?
I know of several 'foreign' UK based aircraft that have done just that. Mind you, I also know of several Americans crewing a UK based Global (M reg), a Canadian crew on a European based Gulfstream and a few South Africans flying various equipment. All on a rotation basis without EASA licences as far as I know. I wonder if the Americans would be so inviting for me to pack up and get a rotational job out of Florida now...