A racing friend pointed out some time ago that if at all possible it is best to attach the aft end of each jackline to a point further forward of the stern than the aft cleat. The idea is to prevent dragging behind the boat - apparently some poor bloke lost his life during an offshore race to the Faralones a few years back because his inflatable PFD deployed yet he was being dragged by the teather and the crew wasn't able to get him back on board in time. I think the idea is to account for the length of the teather so if you're overboard you aren't 3' to 6' behind the transom. On my boat I just loop around one of the foreward stanchions of the stern pulpit before making fast at the stern cleat.
Sailing a '74 Challenger 40' Ketch rig out of San Francisco