Make that 3 dev answers.
NPCs always refer to their visual set.
You might be able to override it by setting the isPlayer parameter to true and back to false, but if that works it will only take what is equipped at that time, it won't keep updating later on if anything else changes without doing the same trick again.
There is indeed a limit set per slot at the moment (we could look into improving this if necessary?):
- general: 14
- helmet: 30
- cloth color: 62
