It seems that P.O.T.S's dampen code doesn't work with Simul mode (as it keeps reseting back to 1 all the time, unless both characters get hit at the same time). I think it happens because of this:
[State -2, Reset var when the opponent recovers]Unfortunately, juggling code also suffers from this. Could you make a small update for your Touhou characters to fix this glitch?
type = Varset
trigger1 = numenemy
trigger1 = (enemynear,movetype!=H)
trigger2 = !numenemy
fvar(10) = 1