"So who else would I go to other than my Goodyear tire expert...They have dealt with HD tires for at least the last 50 years I know for sure"
So please explain to us how, without knowing what your axel weights are he would think it is ok to run 65psi? You are running 245 70 R19.5 load range "G" right? Did you know that your experts who have dealt with HD tires for at least the last 50 years say 80 psi is the lowest recommended pressure to run that tire? That at that pressure it can only safely carry 3415 as a duel and 3640 on a single application. WHAT DOES YOUR COACH WEIGH AT ALL WHEEL LOCATIONS? Use the heaviest side to set the tire pressure for that axel. If you can't get all 4 corners weigh each axel and use that weight to set pressure. There is something You need to (seriously) check on if your coach is 19,000 lbs and divided by 4 that = 4750 per corner but we all know they aren't balanced like that. But that is why it is so important to get actual weights. if you had a front tire carrying 4750 that is more than a load range "G " can handle at any pressure, you would need a "H" at near max psi. I didn't add in tong weight from your trailer.
https://www.goodyeartrucktires.com/pdf/resources/publications/2010_loadinflation.pdf
One other thing about that statement about your warranty?
"the end result was arrived at by miles driven and was totally approved with full warranties for my particular application..."
You might want to read the exclusions in your warranty paperwork. Improper inflation, overloading, high-speed spinup, misapplication, misuse, negligence, racing, chain damage, or improper mounting or demounting. Are not covered. They expect you to be smart enough to keep your tiers properly inflated.
Just trying to keep you safe.
Bill