Great solution!
Keith is correct, it's the extension that causes the problem. Instead of the 1000# being applied 1" from the bend in the hitch you are moving it out about 15". I sketched it up just for future references.View attachment 517840
I don't think anything would happen to the manufactured hitch assy. If anything would fail it would be the plate he welded or the bolt he used. I would put money on the plate. If you think about it the hitch doesn't care if you move the weight farther back. It would be the same as if you extended your tongue on your trailer. I bet if you bought one of these: https://www.harborfreight.com/12-in-hitch-extender-69882.html and just mounted your 3 axis to it you would be good to go.