Russ, here's our experience. I do realize tires are a touchy area on the site.
That's definitely a heavy Scamp
. Ours weighs 2400 pounds loaded for 11 months of travel. We also have 13" Marathons. Though our Scamp
is not as heavy as your Scamp
my plan is to go to 14" tires when the tires are a little older to provide extra margin.
I keep the tire pressure around 46 psi. I also have tire pressure sensors and temperature sensors on my Scamp's tires. Tire temperature increase is a measure of how hard the tires are working.
I will say our trailer tire's temperature's do not go up as much as the tow vehicle's tires. Our tow vehicle's tires go up about 10 degrees higher than the trailer's tires.
Though our trailer weighs 2400 pounds, 200 of those pounds is not on the trailer's tires but rather the 200 pounds is on the ball.
We previously towed a Casita
that weighed about what your Scamp weighs with 13" Marathons and had no problems.