This... there's just zero reason to do it with butt. Especially if you are pulling it. Brisket is a lot more lean, but even a 5+ hour rest seems like there's a point of diminishing returns
The reason isn't too improve the butt - it's to improve my sleep before a big family event with 3 or 4 butts. I normally smoke then overnight in my gravity feed but I don't sleep well since I'm keeping an ear out for a temperature alarm.
By smoking one night earlier and then holding 24+ hours, I would (hopefully) get a good night's sleep, get all the other prep work done, grill up a bunch of chicken, and not be so exhausted during the event. So the question wasn't so much about the long hold improving the butt, it was does the long hold negatively impact the taste and texture of the butt.
I've done these big gatherings twice and by meal time, I wasn't feeling very sociable and it was a struggle to get the minimal post-event cleanup done. I still enjoy it but I think I'd enjoy it even more if I could spread the cooking out across three days instead of two,