I don’t think it is a problem. Team Indiana tested both a long and a wide configuration on the scoring platform without any problem.
When assembled per the instructions a 6WD will not bottom out while going over the bump. If you drive along the bump you have the potential for the robot to bottom out. Make sure you check that the wheels are mounted in the correct position for your chosen configuration. I think the problem may occur if you end up mounting the wheel axles in the holes further away from the end plates.
If driving along the bump is something that you want to do with 4 in wheels there is the possibility to bottom out. The chassis is designed to accommodate 6 and 8 in AndyMark wheels.
The video only shows going up the platform straight on. I don’t trust that all drivers are going to be able to avoid going up the corner of the platform or riding along it sideways. A dead robot in is unpleasant for your entire alliance. One of their partners could push them off but that will take time that could be used for scoring more points.
If you use the wide configuration you could just make it a little longer than 24" and you would have room with the current belts. In the long configuration I think you could cut into the front and back rails and make room for the larger 6" wheels.