Hey bro, I can add the ammo HUD during battle, it's not particularly a problem, but I'll have to leave out the different firing options for the weapon. This is an inventory management plugin, and weapon and combat customization options are outside its main scope. In short, it's not a good programming choice to mix these functions within the same plugin, sorry about that.
Edit: I fixed the item transfer bug between party characters, added the HUD to battles, and made some corrections to the item storage and acquisition logic. I wrote a devlog explaining what changed, and I believe everything is now in order!