Thanks Windwalker, and Wayne again, for the additional information. OK, then I can appreciate that old Master Kuo certainly must have had some very serious abilities and his student David Chin, in view of the outdoor video demonstration at the start of the linked article, had some good abilities too. Or also maybe even more, hard to tell on this basis.
This was also part of my feeling on seeing the originally posted form video. Sceptical in some ways, but not 'this is rubbish' either. I could see that even in the demonstrated form there was/is something special in there. The question remains as to what qualities/content the surviving teaching of Simu Kuo still has. Presumably still OK for health in general terms, but with any added value in this respect, as one might hope in this lineage? And also with some (potential) juice for internal strength, martial qualities etc.? Or has it now turned into more of a museum piece with depleted content where contemporary health needs might be better met by allowing it to evolve? Of course we have no way of knowing from our RSF perspective what aspects Simu Kuo received from her husband, what she trains for herself, and also what she passes on today (to some people).
Absolutely no disrespect intended toward this lady, who I thought made a positive impression in the film. The story here points to the more general issue of whether it's more useful to keep a form (and possibly other aspects) of a lineage as immutable as you can, or whether it's better to allow further evolution while if possible (?!?!) retaining the living content. Meaning: the content that originally went into the shaping the form into its final incarnation.
PS. Just guessing, but I can imagine that executing the punch directly downward in the form helps to bring the whole body's mass/weight and the 'downward mind' into the fist. Then in application a strike executed more horizontally in spatial terms - which of course is almost always what happens in practice - can still exert the whole-body and 'downward' impact on the opponent. As occasional recipient and (fairly low-level) performer of such strikes, I find them quite effective.
PPS. 'Flipping into the air and falling ten feet away'. Probably not 100% the same, but I recall some 'gentle' push hands with Mario years ago when I decided to add just a little 'stupid force' to the mix to see what he'd do with it. That was just what happened then, also very surprising and without me feeling how he'd done it.