I'd be a stickler about listing exactly what's in that "pack" so as to specifically avoid the Schroedinger's toolbox effect; even more so if some of what's in there is consumable.
I think that would defeat the purpose. The whole point of the pack is to make use of the Schroedinger's toolbox effect to avoid having to list long lists of items and to empower player creativity.
Depending on the groups aesthetics of play this might hinder or aid the fun. I got no problem with that. And different groups worried about balance might put different restrictions on it - total number of pulls from the pack you are allowed, or else percentage chance you have the item you want based on intelligence.
It's not even a particularly original or modern idea, as IIRC, Kender had "pack" as a racial ability.