That is a very nice build.... I too started out with a Carry-On trailer from tractor supply... I've two words of advice for you as I learned the hard way and hopefully can save you the agony of future breakdowns at the most in-opportune times.
The rear spring hangers/boxed tabs will fail. The very first trip to Moab, one of mine broke as we were climbing up out of Lathrop Canyon. My welder guy cut both those cheapo things off and welded on appropriate sized boxed steel, I believe it is 2" ID.
Our 1st and 2nd trip out west we spun out the wheel bearings and destroyed the spindle. When you see bearing shrapnel flying up in your rearview mirror it is a heart sinking feeling. We swapped out axles on I-70 west of Hayes Kansas one time, and another time on I-70 just east of Green River Ut.
After the secound failure we got it home and I swapped out the toothpick axle for a Dexter 3,500 lb ez-lube The trailer has traveled some 15,000 miles and we havent' had a single hub or spindle failure. I carry a mini grease gun, and give-em a few pumps every thousand miles or so. Once again, very nice build..