Ok, I'll make this even more clear. I dive a rebreather. It has two handsets, ergo two wires coming from the head. You specifically mentioned a Fischer cable. One of the handsets is wired by Fischer cable. I dive with the specific items you mentioned and I am telling you these things from first hand experience. They are annoying, an entanglement hazard, and a failure point. They are a necessary evil with mixed gas closed circuit diving. That doesn't mean they're comfortable or ideal. That doesn't mean they're a good idea in a recreational environment that doesn't require the specific things that those wired handsets accomplish. There's a reason why things like oxygen CCR's and nitrox SCR's don't use them.
So what you want to do is take an even less robust cable, put it into an environment where it can easily get caught and destroyed, and provides no benefit over the solutions already on the market? Sorry, that's a very poor idea. Your comparison to a set of headphone cables isn't even close to the reality required to function in a marine environment.
Again, I dive with exactly the hardware setup you're proposing, and the idea of making a less robust, unnecessary version, is just a lame idea. If you want your AI on your wrist, bungee your AI computer to your wrist, don't try and go reinventing the wheel with a less desirable solution just because of some fallaciously perceived inconvenience.
