It looks like the spreader bar on the Severne is short. It does have 4 anchor points on it, and the straps spread to keep it in place, but long straps so the movement.
The Prolimt looks to have a much longer spreader bar, but the straps closer together, although the length of the straps is short.
I use the ION Fuel and the bar doesnt move. It
is was a cheap less is more harness and comfy. I see ION, part of the Fanatic/Duotone empire, have now decided to put their 'C' bar on it, in place of the standard bar. Last time I looked, probably 2 or 3 years ago, the complete Fuel harness was a cheap
80 GBP and a replacement 'C' bar alone was 60. Just checked, a 'C' bar is 80 GBP and the good old one 30 GBP.
The Fuel harness with the 'C' hook is now
180 GBP. I bought a spare a few years ago and havent used it yet. WTF are they doing, making a decent harness that more expensive by adding something it didnt need?
www.severnesails.com/harness/pod/www.prolimit.com/product/windsurf-seat-harness-rambler/www.ion-products.com/en/products/ion-fuel-2022-48212-4757?variant=41590081028296