[BJC]

Your wheel base is pretty short for a long robot and it will be pretty difficult to get your Center of Gravity low with the amount of barrier clearance you have there. This would probably be a pretty tippy robot.

However, the idea is very good. Personally, I would push the macanums further out to increase the the wheel base, lower the middle wheel a bit and exchange the outer wheels for tiny unpowered ones.

Regards, Bryan