Simulating extra equipment slots (talismans/amulets)

I’m trying to create additional “armor-like slots” where you can only place specific items, such as a talisman, but nothing else.
I’d like it to work smoothly, including supporting shift-clicks, just like the regular armor slots.
I already tried blocking the slots with an invisible item, but that prevents shift-clicking and forces me to manually clear the “held item slot” (not sure what it’s called).