2013 avalanche-trailer haul mode

Put in this mode, hauling 1ton of stones, 60 miles away, sounded like laboring,  so put in normal drive sounded good. Watched transmission temp, went up to 180 degrees in the trailer haul mode. In the normal mode, temp went down to 160 degrees. Is there something wrong trailer haul mode?

I know in my manual, it says there's no benefit to switching to tow/haul unless you're at 75% of the GCWR....but I would've thought that kind of weight in the bed would qualify....having said that, I pull a 2 horse trailer with 1 horse in it, and when I switched, I found the shift pattern was WAY to aggressive, even with that weight behind it.  I keep it out of tow/haul & run it in "M", that way I control when it's shifting.....

All it does is hold gears longer.. before shifting.