[Chris is me]

I would be very concerned the loads placed on a set-up like this, particularly in traction mode. You can't cantilever everything - when this is in traction mode, there will be quite the bending moment placed on the omni wheel output shaft. It's just an order of magnitude more load than a regular WCD output shaft would have to deal with since the module is effectively a very long moment arm.

Making a WCD-type butterfly drive requires a little out of the box thinking to carefully manage your loads and to ensure they are transferred through the chassis in a safe manner. Look at what 624's butterfly drive did as a good example. Also consider the possibility of the pivot module straddling the drive tube and using plastic slider blocks, etc. to transfer the loads placed on the module to the chassis directly.