Jeff, what are your temps/times like?
Been a good while since I cooked ribs under 225, but I don't think I got as much pull-back cooking that slow. Just don't remember for sure, though. I've always cooked to tenderness, checking for rack drape or with a toothpick.
Anyhow, I target 250* nowadays, and don't even check my ribs for tenderness til I start seeing some pull-back.