I just returned from a 1,900 mile trip with my trailer. Had my tires at 31 PSI the whole time and the trailer handled just like it should and the tires looked like they had never turned when we got home. 60 PSI is just crazy on these little trailers no more weight than you will have even fully loaded.
Just like most of the others, and as I am sure you will find as well, even though I was told 50psi by the dealer, I thought it was a little too high.
I backed it down to 40psi, then 35 psi, and have finally settled on 30psi. That pressure seems to be around the optimum for the "smaller" trailer, matched with the kind of riding we do and the speeds we like to run. Of course, your mileage may vary.
I think most dealers are confusing "Maximum Pressure" with "Typical Running Pressure". It would be interesting to hear from someone with really high mileage on their Aluma.
Started out with the air preessure in the tires too high and they were wearing in the center. Currently running 25-27 PSI in them and it looks like they are wearing fairly evenly. I would say they are a little over half way gone.
Here is the best way to determine the correct pressure for your typical load.
Get a piece of chalk and draw a line across the tires.
With the trailer loaded, drive it for a few miles and inspect the chalk mark.
If it evenly worn, your pressure is right on. If only missing the center, too much pressure. Lower and try again.
If only worn on the edges, not enough pressure but unless you only have 10 lbs or so, I don't think you will see this condition.