PF2e-style Swappable Runes

[Mediator9292]

After playing around with 2e, I've decided to try and implement Runes (enchantments that can be transferred between items) in my 1e campaign. My plan is to have "Runestones" of different power levels/rarities possess a special ability (flaming, hosteling, bane, etc) that, when equipped to a weapon/armor, bestows that enchantment's special ability on the item (assuming it is the right type - weapon vs armor). This means that finding a +2 flaming greatsword means the party has actually found a +2 greatsword with a Flaming Runestone equipped to it, that can be removed and added to a different weapon (so players can better upgrade things like their family heirloom longsword or the chainmail their lost wife made them, for example).

My outline is something like this:
Amethyst Runestones come with a +1 equivalent special ability (like Bane or Keen).
Emerald Runestones come with a +2 equivalent special ability (like Animated or Phantasmal).
Ruby, Sapphire, and Diamond Runestones come with a +3/4/5 equivalent special ability, respectively.

I think I've figured out how to get the Runestone to select a magic weapon/armor on the character - under Item Selection -> Custom Expression, I use
component.BaseMagicI & (component.BaseArmor | component.BaseWep)
Please correct me if there's a better way to do this, since even custom names don't change the item's name in the resulting drop-down list.

The main challenge I'm currently running into is getting the wSpecMagic gizmo to appear and display the special abilities that I'm bootstrapping to it (ipAllying, iBane, etc) as options for selection. Am I missing something, like using the wrong gizmo, or some simple eval script?

Long term, I'd like to get them to code so that only 1 Runestone can be equipped to a +1 item, 2 Runestones can be equipped to a +2 item, and so on, but first I need to get the Runestones to work at all, so one step at a time!