This guy clears up some of the confusion about setups,
in terms of what type of reed should go with what type of
mouthpiece (he does waffle on a bit)

and if you can be bothered he does 2 more videos, i know
JF’s altissimo course works for me and other guys who have
also done JF’s course will agree.

I just like to keep an open mind, and am prepared to watch/try other
peoples approach to altissimo. i’ve tried his video 2 & 3 , and they work
for me. Basically once u’ve mastered those overtones there umpteen positions that
work. In my case as i play a yamaha, i tend to focus more on yamaha players.

as a follow up i got my guardala king mouthpiece out with a no 2 zz reed and nailed the altissimo G in video 2. my current classical setup (selmar solo mouthpiece with la voz medium reed) is slightly harder to do altissimo compared to the guardala king mouthpiece