JAA/JCAB
Not sure how this would be arranged. Having a JCAB checker and a JAA checker in the same checkride.
Who would decide what profile you would fly?
If you fail one ride, do you then fail the other?
I'd try and arrange for a ride the following day (yes, expect to pay for it - don't expect it to be free) for your JAA type.
Good luck
jetflyger