Okay first off, for years, the proven, and IMO, best way to do any BUTT is to cook unwrapped till 203° then WRAP in foil, towel, and in a cooler for at least 2 hours...
SO, again, IMO, if you are trying one unwrapped, then at least try that method so you can actually imitate the way it's been done buy hundreds for years.
BOTH, should get wrapped in foil and towel in cooler for the 'REST'.
The real science and mechanics happens in that cooler!
Me? I'll never wrap a BUTT during the cook... but that's me.