My best time with keyboard is 6:49. My best time with mouse and wasd is...6:49...
Anyways, there is supposedly a 1 minute shorcut in CEZ1. Being on Ultimate will make this easier, and open-GL will make this easier too. When you get to the giant pool of water with the gate the first time, the gate should be up. Hit the spring at the edge of the pool on the box shaped thing. That spring should get you to the small hole with the 1-up box. Next jump out of that hole in the wall, and land on a crawla, then bounce all the way up and thok to the super high ground where the button is all the way across the screen...and the bridge will open. By the way, I've never done this, probably because my comp can't run SRB2 with open GL.