Doing only my 3rd ever batch of ribs today. Past 2 batches were done in 4.5 to 5 hrs. at as close to 225 as i can keep 'em. and turned out quite well. This batch was on for 6 and when checked still a bit chewy, but i became concerned that perhaps i had already overcooked them and took them off. Acceptable but not as good as the previous batches. My question is, what is an indicator that they were left too long? Realizing if they are fall of the bone they are overcooked, if they are left on the grill even longer could they tighten up again? Or is it possible that in some circumstances they would never get really soft but then dry up? Or am i just experiencing the random variability ingrained in the process, and should have left them longer if i wanted them a little more tender? any guidance much appreciat ed.