Why don’t the CAA just ditch the EASA exams and examine for an ICAO compliant standard set of exams which are fit for the 21st century for issue of a U.K. CPL.
Self-study is the norm for Type Rating, so as suggested above just publish a book or two containing what is required and get rid of this prescriptive need to do 750 hours or 650 hours of study. Am sure that a short consultation with U.K. based operators could narrow down what is required.
Some basic up to date AGK with the A320 or 737ng and the CFM56 as a base aircraft to use and incorporating Instruments based on a glass cockpit. Perf, FP and M&B using an iPad OPT. Nav including Radio aids. HPL and Met. Pof without all the stability trivia. 5 or 6 exams ? Or better still just one Nav exam, one Tech exam, and a non-written Skills Test with a ground examiner?
The CAA seems to think if they stick with EASA exams they will somehow convince that they can rejoin, but reality is they really need a system they have the competence to manage. By default, this means something greatly simplified to what we have now!