Fcl.815, Mountain Mating as contemplated by EASA does not give important details as minimum hours requirements, and therefore will be open to interpretation.
The same goes with EASA Fcl.800 aerobatic rating, this time it mentions 5 hours which for all intents and purposes is the very minimum, even spread around many sorties and considering the limited syllabus when compared to e.g. the french aerobatic rating of min 10 hours..
Mountain Rating and Aerobatics are Aeroclub activities, they have nothing to do with ATO's or ATPL pilots, these are run by private pilots animated by passion upheld during years of activity in which they'd invested loads of money and time.
Their instructors have joined the national instructor scheme which does not involve an ATPL and an instructor course but rather an evaluation and 6 weeks training at an academy like the SFACT in Grenoble.
Now EASA is airline oriented, and it shows when if drafts regulation, the one relevant to Fcl.815 and Fcl.800 is definitely lacking in all respects.
It will enable ATPL pilots who with the minimum experience required ( e,g. in aerobatics the basic 5 hour rating + 40 extra PIC hours, will be able to teach).... Mountain flying will not be much different.
The issue is are we going to see young, frozen ATPL pilots with an FI and 200 Hrs TT running the show ?
Mountain Flying and Aerobatics are not ATPL or CPL activities, they are of the realm of highly specialised aeroclubs, not flying schools. Yet EASA stipulates than only FI's within ATO's will be allowed to impart training. And for the FIE's to do the final check, i can foresee more problems. Unless we find FIE's that have been practicing as a hobby at their own experience for ages, how can they be qualified ?
By holding the rating only ?
I can guarantee that it takes a long time only to be safe with aerobatics, and even more with mountain flying as you are operating in an hostile environment at low level during circuits..A long time to earn these ratings and years if not decades of experience to be qualified for teaching.