We also have a 343RL pulled with a 2010 2500HD D/A.
The main slide I felt was out of adjustment when new where we had it adjusted by a mobile guy who knew what he was doing. No issues other than that adjustment.
Pin weight when I last weighed it loaded along with full fresh water tank was about 2000 pounds which for what I have in my truck put it about 100 pounds over the 9200 GVWR. Easiest solution to keep the weight cops happy was to lose 100 pounds which I did since the trailer was stored I went on a diet and am presently 20 pounds short of my goal of 100...
2000 pound pin wieght is well below the capacity of the rear axle and tires plus I added air bags which don't do anything for the capacity but it does transfer some (albiet not much) of the rear weight to the front when pumped up.