What I am suggesting is that the CofA system is far more expensive than the permit system for the same result.
Crash One,
Though I see the point you are trying to make, the "result" is not the same...
Remind yourself that your C of A'd aircraft with the G on the side, is entitled by ICAO agreement to fly just about anywhere on earth. Now I understand that this international recognition is of greatly reduced interest to many "permit" type aircraft owners, and that IS the distinction that everyone needs to be aware of.
I'm sure that from the UK, reaching many other nations in a GA aircraft is a practical possibility. Here in Canada, for 99% of GA aircraft its Canada, USA, and for a few, some Carribean islands, or Central America. Thus, in Canada, many aircraft owners (with eligible types) will surrender their C of A for a flight permit, and a more simple "system". In Canada, it's called "Owner Maintenance". I have one of my two aircraft entering this category now. But doing so strips it's international acceptance, and I have no expectation this aircraft will ever be welcomed into another nation.
That is simply because that other nation has no idea to what standard that aircraft is maintained, and has no international obligation to accept it. When you maintain an aircraft within the ICAO system, you're paying for it (in layers of paperwork, and mandatory inspections), but you're retaining a privilage of international acceptance. It's up to the owner to understand the difference in systems....