Advocate for devils
I have checked your posts again and although you might well be studying to become an instructor your posts do appear to be negative towards CPL instructors (and not in a minority way either).
These guys are the ones teaching you what you need to know, they might be getting a bit frustrated teaching someone you obviously know it all already.
So why not simply pass the ATPL exams and then put your money safely back in the bank and go straight to the FI course. Then you will be a PPL instructor and you won't need a CPL course, you won't spend thousands of pounds and you can demonstrate what a great PPL instructor you are.