Basically, in the player sprite, in the "move player left / right" block, you set the "if player state = crouch then set max speed" to 5 instead of 1.2, which makes it so crouching is twice as fast as going normally. I think this creates an interesting trade-off of if you should crouch or not in certain sections, and could possibly create interesting strategies.

I haven't decided on a final name yet, but maybe something like fastcrouch%?

I've been tossing this idea around for a while, so I just thought it couldn't hurt to just suggest an idea.

what about uncrouch%

It's not a trade off if the best strategy is to crouch the whole time.