Ok, so you know how a bike works, right? It's able to switch it's gear ratio by moving the chain onto different gears. So I was thinking, what if you imitated this on a vex drive? This would have a number of advantages:
It would allow you to unlock more speed as you could use torque just when you need rather than having to have the same ratio all through the match.
You could use a torque ratio to help with controllability while still having speed available.
You could use a torque ratio to accelerate and then slowly switch up to a higher speed as you gain momentum.
You could build up momentum with a speed ratio and then switch to a torque ratio at the last second to get over a bump.
Anyways, this is a very sketchy, however I think it would be cool to develop.