Design you talk about was available years ago. (Where hook moved side to side; so you could twist body to face direction of travel slightly?) Couple of mates still use spreader bar from harness. (Hook slides on a plate along bar) Dont think they are available now; they didnt sell well? ??? There was a plastic version available from Neil Pryde where hook came back to central position under tension from elasticated webbing; they were popular for a few years. Might make a comeback ???