A 5th point is ideally mounted differently than a 6th point. When you have two crotch belts, you are supposed to wrap them a bit around the thighs and mount them such that they are wider at the base. They are intended to actually hold you in. A 5th point, however, is not intended to press against your groin; rather it is just there to keep the lap belt from rising. Therefore, a 5th point mounts a little more forward and just needs to make a straight line (from the buckle to the mount) when taut.
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