As far as I know and from seeing it on Friday, he has not thrown Amanda (pigtail girl) at all. In terms of the double doing the cartwheels across the back of the stage - that was never a thing. Carvel would do the flip over the horse and onto the mat and continue the song. The only reason the double does the cartwheels across the back is to get back to stage right where Bierko had exited, so it seems like it was done by one person. In addition, I haven't heard if Bierko does this or not, (he didn't when I went) but there's also a jump across the stage at the end of The Hammer.
"For example, if I should paint my fingernails green -
and it just so happens I do paint them green. Well, if anyone should ask me why, I say: 'I think it's pretty!'"
When I saw it again the second time (I won lotto on the day of the Flea Market, and had seen Bertie before) the fact that they used a stunt double was almost covered up (And I, who already knew about the change beforehand) until after the cartwheels, Craig came back on about a second after the other Trunchbull exited the stage, so it was pretty obvious to the entire audience at that point (whether you saw that it was a stunt double or not). Also, does anyone know who is his stunt double?