Some observations:
- This only seems to work with vanilla jmod armor, which means additional armor mods aren't compatible. You could probably make it (mostly) universal by just looking at where the armor goes on a player and placing it at that position on the dummy. That way the only things that don't worth with it are weird items of armor that won't say where they go in the inventory system.

- Not only does the armor stand have some odd interactions after it's been copied and pasted as a dupe (essentially seeming to only hold the armor and not provide the quick-equip capacity), copying and then pasting an armor stand disables the functionality on the original one. This seems to be the case for both dupe and adv dupe

-The gas mask seems to work, but the respirators and night-vision goggles don't.

I didn't really add support for night vision goggles, but I may add support in the future. I'll also think about how to fix the problem with duplicates. Thank you for these observations