Ramsay and I had a discussion about 100% and the idea is to stop people from being able to "start" the run having already unlocked stuff. We could make it so you have no memory card, but then it'll stop you from being able to use custom chars, which is a proper fun part of the game, and also a really great opportunity for run optimisation because selecting good moves and stats can really help you.
So, here's the solution!
At the beginning of a 100% run, you'll have to show that the "HIDDEN" screen in Story Mode is completely empty. These cards you unlock as you go through story mode (or in a few cases, slobber knocker) must all be locked before starting your run.
Show that this screen is empty, then select your first character, for either slobber knocker or story mode, and start your timer on selection. Then, once you have unlocked the final "HIDDEN" card, which should be either Shane or Stephanie McMahon or Both, you can stop the timer. By that, I mean when the game pops up with "You have unlocked the following hidden items:" and shows the stephanie mcmahon / shane card, you're done and can stop the timer. Then, go into "HIDDEN" and show every single card is unlocked.
You shouldn't be able to unlock Shane or Stephanie without unlocking everything else first so that'll be a good marker that you've finished.
Best of luck to anyone who's gonna attempt this, it's a real stamina test, and, in the case of my first attempt, a real test of the hardware (which crashed).
If anyone's got any questions about how to do it, or share any thoughts, feel free in this thread.
Cheers all.