I use the manual mode to engine brake when going downhill, and have found this to be quite effective. In my experience, the transmission will hold the selected gear even when I move the transmission back to "D", and will upshift when I apply throttle pressure. I don't tow but I do have a bed...
I also have a '21 Gladiator Rubicon, stock, except for bed canopy and roof top tent. I replaced the OEM Falkens with their new Wildpeak AT4W. It's a slightly more robust tire than the AT3W, which suits my mostly highway driving, with offroad travel on PNW forestry roads. They ride well and...