That's not really practical. The wire is under tremendous pressure when loaded and in contact with a very small area of the shaft. In addition, if the diver is not super careful when loading symetrically, they may "saw" the wishbone side to side to center it, which is super destructive and would remove a plastic coasting in an instant. the steel cable will last a while and fairs better than dynema, but the real solution is to use shafts that have a rounded notch or rounded fin.
If a diver is using a shorter gun, which does not require grabbing the actual wishbone to load, then some progressive cable fraying is not that troublesome if you keep your hands off it and wear good quality gloves. In other words, for a shorter or medium length gun, if the diver can just reach up and grab the sides of bands after the wishbone they only have to touch the latex band material.
This won't work?
https://www.makospearguns.com/Mono-Jacket-For-high-profile-sharkfin-shafts-p/mmj.htm