Adding rack to rear of trailer

I added a generator and a work box to the rear of my TT and have not had any adverse handling effects. Its a champion 4000 gen and the work box holds all the blocks for leveling etc. Maybe 300lbs at max. What I did was to get 2 of the bumper receivers and then go to a steel supply place and bought 8ft of 2inch and 10 ft of 4x4 steel. The receivers I bolted to the frame, then I determined the length needed to match up to the dimensions of the gen at the work box. The work box I mounted into a harbor freight receiver carrier so it could be bolted on to something. The rear 4x4 is then bolted to the 2 2x2's. everything is solid and has not had any issues. Got the idea from a guy I saw in mississippi who was traveling down the street with the gen running so he could have ac when he stopped. Only thing was his set up was like a porch with diamond plate covering everything. The spare tire I carry in the truck bed now but have been contemplating mounting it under the upfront A frame to counter any weight loss due to the rear setup. So far so good. Also my son in law towed the trailer with his new f150 and had no issues with it, so 2 trucks for same trailer no issues.