Where did you buy that ??????
Pretty nice and all tig welded too overkill but really nice, I was showing my welder buddy your work especially the plug welded swing arm pivot (maximum overkill) and he liked it, thought you tried to hard(overbuilt), he's usually guilty of the same thing.
Your subframe is stiffer than Claude's Why ? Though I wonder if you may be onto something with your extra support. You might as well add a loop where the purple level is sitting for an auto battery box, get some extra amps and move the weight to the right.
If you as nicely with the body it'll be lovely.DB
Patience: A minor form of despair disguised as a virture.