Configuring a trapeze
A simple ''light line'' from the stern with a terminal "J" hook to fit to your harness would be proper. There is danger in all this as the more ''clutter'' you add to a trapeze arrangement the greater the danger of a non-release or entanaglement when you (you will) capsize. The greatest danger in singlehanding while on a trapeze is that all the harness connections should be "bombproof'' for instant release - especially when you are underwater and upside down! Be sure to always wear a very sharp sheath knife!
For boat control and recovery "after" you fall off, simply drag a light polypropylene line with a loop in the terminal end, the other end is connected to the tiller. If you can grasp the loop, a strong pull will swing the tiller to full athwartships position ... but then you probably will have to re-right the boat.