Ah nice! Not that I'd ever do it, have you tried dual hand crossbows? Does it literally give you two ranged attacks per turn?
So I tried on Astarion and you actually get the offhand attack as a bonus action (like melee dual-wielding). But it also bugged Astarion to the point where the game crashes, whenever he climbs a ladder or tries to unequip the crossbows. Sooo... maybe make a save before trying that out.
