As for cooking poultry low, in the past it worked o.k. for me. I wanted to get it above 300, it wouldn't do it in my UDS until I opened all the vents.
I had a pleasant surprise when I did get it hot though. crispy skin and meat that was not all dried out. Maybe I used the wrong tool for the job?
KCBS CBJ Caldera Tallboy, Meadowcreek PRS60,Blue Weber OTG,2 UDS,and other Weber stuff