In regards to Bangkok...
The chairs in the pyramids should be legal because the glossary definition of 2.5 high says:
Two and One Half High Pyramid:
For Level 6 Only: Pyramids higher than 2 1/2 body lengths are prohibited. Pyramid height
for a “Two and One Half High Pyramid” is measured by body lengths as follows: chairs,
thigh stands and shoulder straddles are 1½ body lengths; shoulder stands are 2 body
lengths; extended stunts (i.e. extension, liberty, etc.) are 2½ body lengths. Exception: an
extended stunt on top of a thigh stand is allowed.
It's the "almost" shoulder stands I'm more concerned about. The flyers feet are at collar bone level of the mid-level flyer... thats sketchy to me. Difficult to judge about the legality of spotters because we can't see the back. But spotters can touch the stunt and still be legal, except in 2-1-1 thigh stand tower pyramids.