Wow! Very interisting! I am a retired engineer. Acoustical things continue to fascinate me. A few years ago I toured a music box collection/museaun and was astonished at the difference construction of the "box" made in volume, resonance and tone. The docent had a box with a removeable cover. Removing the cover altered the acoustics of the mechanism and it did not sound the same. Banjos are no doubt their own peculial art. Nice to get the history lesson. As a structure, a hoop of rectangular section is a fairly simple one to analize. If the thicker rim section produces better stability yet you would like to have a lighter instrument, there are some standard treatments to optimize (lower) the weight. The thicker rim is the simplest stiff structure though heavy. A rim with internal ribs (circumferential) could in theory have lighter weight though it would be a bit trickier to manufacture. Generally, simple pictures are best. Your instruments sound very good. I love your videos!
