We have a 2018 Tahoe LS without the max tow, towing a Grand Design 15RB rear bath LOA 20’, between 4,000-5,000 lbs. fully loaded. Tows like a dream, and with the Curt Echo bluetooth brake controller braking is easily configured for both g sensitivity and brake force, touch iPhone display with fingertip to manually engage brakes if desired but never had fishtailing so never was required, more of a security blanket to know that it’s an option. Last summer towing in the Pocono Mountains car would pull mild hills 55 mph in 5th gear at 2,000 RPM, and occasionally on steeper hills drop down one more gear to 4th gear 55 mph 3,000 rpm. No hint of over heating either engine or tranny, both might get a few degrees hotter on the way up but cool down on the way down or on the flat and level. Truck had 118,000 miles on it when we bought it used a year ago. We put maybe 3,000 miles of towing with it in the northeast. I changed ALL the drivetrain fluids the first week we owned it and haven’t had any drivetrain issues. Uncertain how 1st owner used or maintained it. Your concern about a couple of hundred pounds of payload either way is milking mice. In the short term won’t make a difference, in the long term towing is gonna accelerate wear, don’t expect to get 300,000 miles out of her if you do a lot of towing without some major expenditures for tranny, brakes, wheel bearings, and maybe engine. These are cheap GMs, not Mack trucks. As for tongue weight, single axle trailers recommend 10% tongue weight, if you get a bigger dual axle trailer you may be able to use 5% tongue weight. In either case driving at the speed limit when towing is WAY safer than 9 over. You will get tailgated no matter how fast you go, lots of idiots out there. Instead of wasting time worrying about a few hundred pounds either way, worry about wether to stop at McDonald’s or Burger King. Just my $0.02, take it FWIW.