Anyine did their own bicycle trailer hitch?

Most commercial solutions are designed to be connected to one side of the back wheel hub area but I would like to have it centered so the rod connecting the trailer can be shorter and allow me for tighter turns and shorter rig overall.

I suspect that 2 inches from the end of back wheel would be perfect, but pi related could be a less of a hassle because I already have rack.

Do you have experience with some weird custom designs or ridiculously simple but effective coupling mechanisms? Experience with diy trailers is also welcome.