Well, they're incompatible. I didn't optimize for those, because I figured an episode using this would hardly employ characters that don't work with it.
Wario has Power-Ups that aren't in SMBX2 (Ex: Zombie Wario), It would be nice if Wario was compatible.
It may be that it only happens when in editor but if you enter a new level via warp exit, the player powerup gets reset to the ice flower powerup. I have no idea why this happens though, probably an issue or oversight with saving the custom powerup data of the player...?
someone mentioned on discord that the reserve box was being filled when you get hurt and grab a dropped reserve power up, so i made a small edit. here's it is.