Wow, yeah that stuck in the wall thing is very odd.
I recommend that you at least add a rough workaround.
type = changestate
trigger1 = frontedgedist < -550 || Time > 100
;trigger1 = abs(Pos x) > floor(gamewidth/2 + 550) ;(Gamewidth/2) + 550
value = 3023
so add Time > 100 as a failsafe. Doesn't look as smooth as when the move is used on the proper stage bounds but t least the fight doesn't get jammed up.
Also, determined my original trigger suggestion abs(Pos x) > floor(gamewidth/2 + 550) can just be replaced with frontedgedist < -550