[Violist]

I'd interpret "Presence Permitted" as somewhat different than "Willing" since, as was pointed out earlier, "willing" could mean that Kaylin isn't necessarily concious, just willing to be in the area, while "presence permitted" would - to me - imply a concious decision to permit someone's presence. Of course, that gets back to the problem of how does the trap know...

I suppose it's highly unlikely that Kaylin will ever try to get someone to fetch her spellbook for her, outside of the party, so I suppose the trigger condition "Detonate on object touch" would work once the rest of the party is attuned.