Techgun items currently have only a few tags available for editing:
camo
ammo
ammovariant

This is not enough for RPG servers.
It would be nice to be able to create different variations of weapons and armor with modifiers and register them in boxes with loot.
For example "rusty pistol with -10% damage" or "power armor mk II".

Thank you for your cooperation!

Those NBT tags are not meant for manual editing. They are needed for the weapon to function. NBT tags are the best way to store per item information.

But your Idea about customization with nbt is interesting, I might consider it.