I don't get you wrong, Tye, you make valid points. And thank big Bri for the forum, I simply spend too much time here!
The archived post includes five cables with which users have enjoyed success. Maybe some UA5 users will chime in with their specific cables, but I think this is one of those situations in which there is no consensus on the "best" optical cable for the UA5 > JB3 combo. For the recording we do, optical cable quality for field recording is really only an issue if you use a really crappy cable that causes problems, IMO. If you have a monster audiophile playback system, you *may* be able to hear the difference between optical cables during playback. But then again, you may not. And while recording? I'll bet big bucks against someone identifying an expensive audiophile optical cable v. a quality consumer cable.
FWIW, just about any reasonable quality optical cable (like the five referenced) will work well UA5 > JB3. Only real question in my mind is whether you want right-angle cables or not, and if so whether to get a cable with built-in right-angle connectors or simply use right-angle adapters.