Granted, my trailer is a bit bigger than yours, but I took my first trip with the tires each at least 15 lbs low (65 lbs max and suggested) and towing was miserable. On the way home I was thinking about selling my truck and getting a bigger one (which maybe I should have done in the first place). Once I discovered the tire pressure was so low, I filled them up to max and voila! It's like a completely different trailer. Truck tows just fine and all is well. That was the LAST time I will ever leave the driveway without checking and topping off the tires.
Remember that with your tires at lower pressures, they create more friction and thus more heat, and heat and friction destroy tires.
So, needless to say IMO, fill 'em up!
2014 Jay Flight 28 BHBE
2015 RAM 2500 6.4L HEMI, Tradesman 4x4, 3.73
Blue Ox SwayPro (BXW 1503)
Upgraded from an REI internal frame backpack and a Eureka 1/2 dome tent!