Towing new

I find this idea of breaking in gear sets to be quite interesting because in most heavy equipment applications it is never done. How does a motor home owner not tow for the first 500 miles? After searching the web for information I find the recommendation to not tow for the first 500 miles over and over again. I also read that after the first 500 miles the wearing in process has hardly started. What I found interesting is that there is some good reasoning for why a gear set should be run in. Apparently new gears have a roughness to them or small mountain peaks if you will that can protrude through the film of lube oil. As these peaks meet each other under heavy load they can produce a lot of heat. This heat can thin the oil exposing more mountain peaks causing more thinning of the oil and accelerate the wear. Because the real heavy duty applications of gears never have the priveledge of getting a break in period and failed gear boxes is something I have rarely seen, I doubt that towing a trailer down a hill is going to overheat a differential. In the future I will likely stop and check the temperature of my differential every 1/2 hour or so for the first while, if I need to tow with it prior to allowing it to break in. Something that hasn't been mentioned that I think is valid is this: if driving easy for the first 500 miles provides an adequate break for your tow vehicle then it stands to reason that towing a trailer the same weight as your truck in 4 wheel drive would provide that same level of protection as it would put exactly the same torque through the gears as if you had no trailer on running in two wheel drive.