I wanted to note what someone told me when they saw the harness and heard the issues I had with arms falling or shoulders being too low. There is a tactical riot suit for police that has hard shock-plates. They use belts between parts to hold them aligned, especially on arms and shoulders. See the belt straps from shoulder tips to forearms?
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It's actually surprising how much this design is similar to the exosuit - it's just plastic instead of metal and doesn't look as cool. I am going to be converting parts of my harness into this style to make it resilient to tearing and make it more comfortable to wear.