You know, I just avoid the tow mode for that very reason. I prefer to manually shift my automatic. When it is tow mode, it screams and jerks and revs up whey high for me.
I can shift from D on down and accomplish the same thing, it seems to me, without it sounding like its going to explode and jerking so badly.
We just came back from 1500 miles and much of it was in the Rockies. We only crossed one pass going and coming that was almost 10,000 and I was towing a Jeep. I just like controlling the tranny myself. Color me old fashion, stupid what ever. I have done that for thirty years, never had transmission problem and have no brake or control problems. To each his own method. Done it on Fords, two Chevys and a Dodge.
Paul