You or your rigger should contact the manufacturer before making this mod just as a matter of good practice. When in doubt, contact the manufacturer. A much simpler method I have seen is to leave the top of the loop sewn on parallel over the top of the riser, but sew the bottom end at a 90 degree angle to the riser. See what Sunpath has to say about that.
This sounds like a CReW mod to make it easier to grab the front riser dive loops. Even if you forget the cable and just fold the loops in half and sew the rear edges together, they will be easier to grab.