I think you are exactly right. I think I should of kept cooking, they were edible by internal temp, real juicy, but not quite pull off the bone, real close, but did have a little meat sticking to the bone in certain areas. I cooked them 215-230... mostly holding 228 for about 5 hours.
The snake method is real simple... I line the outside of the charcoal pan 3/4's of the way around. I fill to the top of the pan and taper down towards the center, there's probably a 8" hole in the center charcoal free. I only fill 1/4 of my chimney and get it all white and set in on one end of the circle. Here's a pic of what's going on in mine now.
This really may seem chaotic, but I put a lot of thought into the lay of the lump. I don't like a lot of air gaps with bigger chunks, I don't mind a few bigger chunks if I can fill in around them, but if they are too big I smack them with a hammer to make them smaller.
This really holds temps well. I do get some variance between 220-240, but it really hangs in 225-230 for the most part.
Today, things seem to be coming along quite nicely There's a rack below, hope the chicken drippings don't mess anything up.