fiber as an ethernet link is packetized and has error correction. 1Gbps and 10Gbps stuff is just OOK blinking LED on and off. Pretty hard to screw up unless you have a chipped ferrule/facing, dirt on the fiber, or dirt in the connectors.
I'm going to say turbo product codes
can we maintain high fidelity satire close to the shannon limit? what do the varying code rate waterfall curves look like for satire FEC on modern equipment?
The best I can think of is Hamming codes, because "hamming it up", but improvements would be welcome.
Latency maybe, but the article doesn't talk about it, and this is typically solved the same way it is inside your computer when feeding the sound card: deliver too much info then wait. The real time delivery constraints that you can patch into the Ethernet stack on Linux are only necessary for reducing roundtrip time.
I can see the logic behind a properly isolated switch - for example, I have optical everything as my amplifier has a terrible habit of turning switching power supplies into chainsaw noises. Anywhere I can isolate shared noise is a win. But that's achieved with amazonbasics toslink cables, not .. magical pixie dust, or whatever these guys are selling.