They did not look under inflated at 20-22 but radial ply tires always look under inflated
The increased pressure did not create a harsh ride at 75F. The sidewall flex is still very good. I suspect the ride will be a bit harsher at 60F. I will find out this weekend.
For those with bad backs, I would not run these tires lower than 18 PSI. You should get "decent" wear at that pressure...Better wear than bias ply tires.