Why are the wheel wells indented so much for just 1" wheels? You're greatly decreasing your available bellypan space.

What's with the double set of sprockets on each wheel? Just lazy to make spacers, or do you have a reason for doing so?

What is the reasoning behind not having your gearbox plates backed by the frame? The spacers there make me iffy about the strength. If your goal is to save space with the inverted CIMs, ask yourself if it is really necessary that you save that much space. Because I feel as if lessening your wheel wells will save plenty of extra room and you won't require a design more complex than you need. I'm sure a 2 CIM WCP DS would work perfectly in its place and save you a lot more time and trouble than this custom design is worth. If you still insist on doing this kind of transmission, I suggest you take a look at this one I made.

If you really want that low a low gear, shoot for a high gear around 15 to 16 ft/s.

If you have any more questions about drivetrains or transmissions, feel free to hit me up with a pm. This has a lot of potential, but you need to have more focus on what you want to accomplish with it and how it will fit your team's needs and resources.