There is also an option to have a one time shifting transmission that starts in the high gear to accelerate the light robot, but then shifts into the torque mode to carry the goals, play defense, and climb the platform.
You don’t have to use expensive pneumatics for switching, as it could use some elastics to do that one time shift, triggered by another mechanism.
Similarly, you could start with 8 motors connected to the drivetrain and, after the initial auton rush, shift some of them in similar way to the secondary functions, such as mogo or ring lifts.
Finally, there is an option of a non standard X-drive that, compared to a regular X-drive could give your more speed in one direction and more torque in another.
Just be mindful that the more it is tilted, the more power will be lost in the speed direction due to the friction in the omni rollers. Less power means less torque and lower initial acceleration. If the robot is light enough you may still gain some fractional seconds advantage with the higher speed, but that is not guaranteed.