How about leading the safety line forward from the main blocks? I have some grommets in my tramp in line with the shrouds, more or less. Put a heavy line through the grommets, a good stout ss ring on that line and run the safety line through the ring, to the harness. Then, if you go overboard the safety line, hopefully won't destroy the steering link. If you experiment a little with the length of the safety line, you'd be bobbing along near the rudders and, hopefully, could bring the boat head to wind.
I had an incident where a crew member become separated from the boat when we tipped once that caused me to call a mayday as I had lost sight of him. The wind was blowing dogs off chains, with about a two foot sea, and my boat was making 5 kts while on its side. Unbeknown to me, the slug that was my crew that day could not swim or should I say made no effort to get back to the boat. Boy can those Coast Guard boats move!!!!!
From this incident I had put some thought into this as where we sail stuff can happen real quick even to an experienced sailor/good swimmer and I don't want to make any phone calls to the family.
That said, I did this with my 5.8 tramp, that is had some heavy duty webbing sewn into both sides with a loop to attach a Spinlock elastic safety tether. One was right in front of the main sheet traveler cleat and another just after the tramp bag for the crew. Never got the chance to test under real conditions but it worked OK when testing it while having a crew on board. And wasn't too bad when we tipped. When I added a spinnaker to the boat, it turned out to be a mess fouling line and creating some confusion.
The next thing I tried was a pad eye on the rear beam and the main beam that we could attach the teather to, that worked OK but was a pain sometimes I would forget to unhook when tacking or gybing.
I also tried putting a heavy duty D ring over the foot strap, tacking the strap to the tramp with heavy duty webbing at both ends, and attaching to that. But again one more thing to do when you're tacking. Nothing big when your pleasure sailing but when racing it was.
