O.K....had a good night's sleep...
But seriously, folks:
I'm quite interested in the whole tire-pressure question, and since I'm about to buy new tires
I'm going to conduct some road tests.
I've towed the same combination for thousands of miles with the tires
at 50 pounds, and while I've totally mastered the "sway" problem inherent to the rig (without special equipment), I'm not satisfied with the quality of the trailer ride.
I literally cannot carry graham crackers for s'mores as they're reduced to crumbs by the time I get to camp....
The problem in my case isn't the axle
or its suspension components, which are in good condition. But the tires
are part of the suspension system, too, and certainly major contributors to quality-of-ride.
I'm going to replace my tires with identical new ones, and will experiment with different pressures to see if there's a beneficial effect on the ride WITHOUT any detrimental effect on stability. The timing is perfect since the next several trips we're taking are over roads I'm very familiar with, and I know exactly where the highest sway-potential spots are along the way.
When I've gathered all my Very Scientific Data, I'll post a new thread on the subject.
Thanks to the O.P. for bringing it up, and to the rest of you for making me think about it!