I have fit these "speedframe" stud systems before, they are really flimsy until you fit the plasterboard over them, then the plasterboard itself becomes partly structural, absolute sh*te in my opinion unless it needs to be a 1 hour fire wall, completely non combustible!
Agree with @callatiler , it surprises me that they used real ply, its often OSB (not sure if that is better or worse than ply TBH)
Agree with @callatiler , it surprises me that they used real ply, its often OSB (not sure if that is better or worse than ply TBH)