Yeah, with port butt, there's no noticeable difference in the final product between cooking them at 225 than at 250 or higher. On an big green egg, I cook them at 275 dome (thats about 250 grid temp).
Your going to lose 50% or so of the product during the cook.
I rest my pork butts anywhere from 0 to 4 hours depending on when I want to serve them. No problem taking them off and pulling immediately.