When there's a lot of equipment to sort through the equipment screen is clunky as hell. You can only scroll through available equipment in one direction and removing equipment from a soldier requires you to find an open spot. This causes many more mouse clicks than necessary.
I suggest an extra button to back scroll through the equipment list and a button you can drop equipment on that will automatically remove it from your soldier.
It's likely fine as is for vanilla but when the mods start dropping lots of equipment on you it gets tiresome.
Great work on this project btw - I have sunk many sick days into it now