The CAA can issue all the memo's they want. They can not change JAR-FCL and that is what counts.
The CAA issue many "restrictions and memos" but all a pilot has to do is move their licence to a JAA country with no such a restriction and say
to the CAA.
You may be surprised to find that the CAA find's itself in the position of having to sit back an watch while a very large number of the UK pilot population operate with JAA licenses issues by other countries which makes the CAA restrictions meaningless and at the same time administer JAA licenses issued to many pilots in other countries - especially ex military from various european countries who do their civil training and tests in the UK.
Like I said it is possible to get an ATPL with only having actually flown the aircraft on the few solo hours that form part of the PPL course and during the various tests. i.e. very little hands on experience.
The important thing is to a) operate the flight safely and legally (insured) as well as making a truthfull record of who did what during the flight. So that if someone does come and check you have recorded just what part of the crew you were.