Like above, a couple things may help........
You can easily go at a higher temp without any ill effects......I shoot for 260~275 generally.....gets done faster, comes out just as well, plenty of time at that temp to add as much smoke as you'd like....
I get nervous when someone says 215 because if you happen to be reading off a lid therm, it's way under that....like at 180 or something.....could possibly even be not foodsafe if you go uncured at too low of heat....that's what Tenderquick & other curing salts are for......
Don't be fooled by a smaller piece, as it's going to go by thickness much more than total mass.......heat needs to get to the core & stay at that level for "X" amount of time.....
Most times, I'll cook all the way thru (likely around 200, but slide easy probe tender is the best indicator...or bone wiggle / release, see below), let breathe for 15 minutes to stop the cooking mostly, then dbl. foil wrap, towel around that & into a dry cooler for minimum 1-1/2 hours........this is the most important part from my own personal; perspective.....it needs to sit still & allow the juices to level out & reabsorb all thru the piece.....then you get this:
Bone release.....the bone will pop loose from the meat & come completely clean.....
I tend to move it around or wiggle, but then leave it in place so as not to disturb the shape of the piece....
You can wrap during the cook....some people do to get a good ending color.....find where you like it & wrap at that point....
It will also then speed up the cook somewhat....