I'll add my 2 pennies here. I have just replaced my tires and during my research from various tire companies, I have been told that you should have at least 10 psi below maximum on the steering axel. On the rear duals if the PSI is suggested to be 75 psi it should be a max of 70. The reasons given are for stability and anti wandering. Plus unless you have the same tires the MH came with new there is always a variation.
I spent hours researching tire and size in order to stop wandering and increase stability. Both have achieved my requirements and my receipt shows tire pressures. It should also be remembered no two MH are loaded or driven the same way, and any sop suggestion is a suggestion and not a 100% recommendation.. Talk to a tire guy then go else where and talk again.. when you get the same response three time act on it.