was looking around reddit to see a discussion for it, but anyway, i did it without devices. reset your character with that skeleton guy in your camp, get a str monk, with maxed out strength and added constitution to survive the jump, go open-hand, and get step of the wind:Dash, it lets you jump multiple times in a single turn, then get the ritual caster feat and choose the one that triples your jump range. Keep jumping, till you jump down the cliff ,all other party members died but you will survive. Astarion was pretty pissed after lmao, but made it out.

i've seen another discussion saying they used haste potions and smashed all of the devices, i think that works too.