Given the tight time table of the adventure, what role if any could an artificer PC play in RHoD? Functionally, the artificer can act as a trap-detector like a rogue, and can help to identify those magic items. Anything else?
Apart from infusions, UMD on any wand or scroll they can get their hands on? Probably use a Dedicated Wright homunculus to do the crafting while they're on the move.