Well, I have not read your magnum opus yet, but if I had room to spare in my rack, I would rack my semi-mod up until that space was needed for individual modules. I would then, put my semi-mod back in the original case and place them on a small multi-tier shelf system. Along the lines of what KV Gear makes.
(https://synth-rise.com/products/um2?variant=39309119946937)