however different story with flight school they would charge according to license held eg cpl rates if cpl license held ppl rates if ppl held
Surely charging is down to the Examiner who is independent of the flight school!
it is not a question of medical.
That is simply one scenario that lead to the question; the answer is the same regardless, an Examiner who is certificated to conduct Class Rating skill tests and proff checks may do so for any licence holder. If not, you would need a FE(ATPL) to do SEP revalidations for ATPL holders!