I will tell you first off, i don't own, or know chit about UDS's except - they are brilliant, cool BBQ machines that allows just about anyone to make great BBQ.
Secondly you did a GREAT job! Not sure if you even need this on a UDS, but did you "season" it when you fired it up for 12 hours?
Also remember, when you put cold/cool/even room temp meat in there it will drop temp, more meat, longer it takes to get back up to your desired cooking temp...... i think with UDS too
So get it hotter (290?) than what you want before you put in the food, that will make it easier to bring up to temp after the food cools it down.
I do know this much, For BBQ, cook between 200min (i like 225) and 250max (rack temp), until desired doness (for chicken 165-170 internal temp).
Good luck brother, DON'T FORGET PRON OF THE COOK!
And a little passing advise to keep in mind - don't try new recipies, or BBQ for first time - to serve to company ... even inlaws
But good luck to you anyway. I'm sure you will get a bunch of UDS advice on here, listen to them, they know their chit!