Weapon Modification Extension (PF2) - Seeking Example/Inspiring Extensions

tl;dr If you know of any extensions that allow for deep customization of weapons, please let me know. Currently trying to cobble together an item crafting/modification mod for Pathfinder 2e.

Currently converting RGG's 52-in-52 'Gadget Crossbows' PDF for personal use. The general principle of the material is to allow for modifications on a crossbow to allow for various bonuses. The pricing is based on the base price of the weapon, and there are various limitations in place to prevent gadget abuse.

The following example is not found in the module, and is for demonstration purposes only.

Quote:

---

Quick-Stop Lever:
Price (80% of base cost)
The crossbow is outfitted with a lever that allows the firing of the crossbow to be interrupted. Although the crossbow fires, the lever lifts a block of wood that stops the bolt from leaving the chamber. Due to this, the sound and force of the crossbow is felt at close range, but deals no damage. The gadget gives a +2 item bonus to Intimidate checks made by using the crossbow in this manner.
Restriction: Can only be applied to hand crossbows.

---

I'm intending on building out a new category of items called 'augments' or 'modifications' or something similar. Then these items can be nested into a weapon, armor, etc. The same idea could be applied for things like the Skulls & Shackles ship building rules.

Goals:
-Set up a new category of items
-Allow for the 'augment' price to be calculated differently based on the weapon it is applied to.
-Allow for the augments to be restricted to specific groups of items. (Weapons, Crossbows, Bludgeoning Melee Weapons, Vehicles)

If any of you know of something similar, I would love to take a sneak peek. Currently looking at the coin weight modification as well as various tutorials from damned.