I think it's a great idea. I can see some of the downsides or the potential liabilities but that exists in almost anything.
I do have a question though. How hard is it to make the bends needed with the rails? The metal is 0.125" thick which isn't huge but isn't thin either. It appears that a 180* bend is needed for the ends and the underside of the rail at the axle looks to be a fairly difficult to pull off. Is this something that can be done with C-clamps and vises easily?
Keep innovating Rodger and keep us updated on a 2nd gen offering