I would reach out to the Lull shop and ask them which they prefer. My experience with prewired pre's has been mixed (just from a fitting and aesthetic point of view- some looked like a rat's nest when they were in the cavity), so if you're having them do it, might be best to see what they want.
Which Lull M5V did you get?
Yep, call the shop. They're super helpful.
(or at least thinks so, some