Yeah I can understand why you want to take that precaution. It's better just to prevent any problems, instead of having the problems, delaying the tourney, and having possible DQs.
I don't know if/how textures alter Transform though.
"In Brawl, the animation for the transformation takes significantly longer, but Zelda/Sheik is invincible during the majority of the transformation. This is most likely due to a software limitation (The larger disc that the Wii uses having a longer average load time than the Game Cube's smaller discs), not an intentional change, as the transformation time is the same when Zelda/Sheik's reaction time is slowed down by an item, assist trophy, or practice mode. While making the transformation more punishable, it is possible to use this move to dodge Final Smashes such as Cook Kirby; and Tabuu's Off Waves. "
Unless textures add loading time. Although if it does, I can only understand a few frames worth.