dobbin1, I understand that if the RF is teaching the AOPA/BAeA syllabus, then that will 'grandfather' a right to teach the Aerobatic Rating. Which isn't surprising, given that the AOPA/BAeA Basic Syllabus was aligned with the Aerobatic Rating course a couple of years ago.
However, ad hoc aerobatic training to some other syllabus might not be recognised as qualifying.