Least expensive fix, and one that won't get you dirty, is to spend $10 at a truck scale and weigh the coach. With a rear queen bedroom including a slide, and another slide just forward of the axle, I doubt you have 4600 pounds on the front axle. You can look at
Michelin's Chart and figure front tire pressure using half the scale weight for the front axle, Be sure to use the "Single" values.
Michelin would like us to get weights for all four corners, and that's why the numbers are presented for a Single tire or a Pair of Dual tires, but not the Axle Weight, which would be double those numbers. Still, Axle weights, Front and Rear, will get you on the way. I doubt your front axle will call for more than 55-PSI.
Tow your S10 to the truck scale. You'll get a report with weights for:
STEER - RV Front Axle
DRIVE - RV Rear Axle
TRAILER - the whole S10
80-PSI in the rear tires may well be right. With a 160" wheelbase, the 29B is going to be tail-heavy with two slides back there.