So does Archivist break Sanctuary? Information overload uses your spell save DC but you aren’t actually casting a spell, and since it’s save based you aren’t making an attack roll either.

Also I feel like the many handed pouch got a little underrated. By strict RAW I think you can put a bag of holding in there which effectively lets the whole party access a collective inventory, and you can use the Archivist telepathy to talk to 5 people with only one infusion (in case you want to keep them all for yourself). There also seems to be a lot of potential with the spell storing feature, if by RAW a tiny servant can activate the stored spells and if you had one of them in there they could be ready to drop a healing spell on anyone who went down.