Glad you're OK, and thanks for being honest and posting the carnage. That is the most valuable way to show newbies about why the experienced builders do things a certain way.
I'll post a pic later, but I was an idiot (what else is new?) and rode without a helmet recently. Fortunately I was wearing safety goggles (that look like sunglasses), and took a spill. My pride was the part that suffered the most hurt, but I also now have on extra scar with which to impress the ladies at the rest home for the elderly. If I hadn't been wearing safety glasses, I might be typing this through one eye.
I'm impressed by the plastic cell-holders in a honeycomb layout. That is the way I would do it. This is ES, we need to be the ones to lead the way in providing links and resources so a builder can get on a website and easily draw two plastic side-plates for holding 18650's, and then paypal a separate website to 3D print them out and ship.
edit: I added you to the KFF index in the battery section stickey:
https://endless-sphere.com/forums/viewt ... 7#p1254427