I know there are videos of other teachers doing that too - notably I can remember a couple videos of Chen Xiao Wang doing it.
As I understand it - it works for healing too - when someone has tension at a point in their spine/body, you can push through to that 'spot' (the kink in their posture that allows you to "push" them as it were), and instead of actually pushing them off balance, quickly release it using the opposite vector to that which you pushed it with - with I think helps release the tension there...
Similar to using reverse pressure to "suck" out the tension if I am explaining that at all.
I really appreciate the punniness
and my post wasn't aimed at your previous discussion with other folks, I merely interrupted and posted what I saw as relevant FYI.
Solo Zhan Zhuang is very important for full benefit and..
IMO, one can absolutely practice Zhan Zhuang without a teacher and see great benefit as long as they follow natural method, as you touched on!
I really agree with you about your point in trying complicated things without a teacher too