Well, being a kyu-grade male, I've never worn a hakama (folded them, lol, but never worn one) So I can't really answer that. A corset, on the other hand... ahem
Actually, haven't worn one of them either (honestly)
That said, would a corset not help you to keep your posture?
Yes, I realise this is the humour board and you were joking... but still, such issues need to be addressed!
Anyway, all the Yudansha swish around in frocks (as I've heard a few sensei put it), so hey