Is it possible that you are using a Linux distribution that still has Pulseaudio instead of Pipewire? That would cause unnecessarily high latency in the audio stack on the machine.
Do you happen to use a distro that excludes patent encumbered codecs? For example, if you were on Fedora, you might want to install pipewire-codec-aptx from RPMFusion?
Some companies allow specific Linux distributions (like RHEL) only. Maybe that's something for your case too? At least there is "Enterprise" in "Red Hat Enterprise Linux" ;-)
Audio is a mess. To have low latency in my DAW (Reaper Linux Version), I have to launch it via the command line using pw-jack reaper, otherwise it won’t recognize the audio device or uses ALSA or Pulseaudio both of which have way more latency than JACK
Most modern linux distributions use pipewire, which should have lower latency than ALSA or Pulseaudio, if configured correctly even lower than Jack. You might want to try that instead, especially when updating your linux distro.
For your audio quality: Have you installed pipewire-codec-aptx from RPMFusion? Fedora ships without patent encumbered audio and video codecs (and some other software) for legal reasons.
As far as I understand, the latency is improved by the different speed of light of the DNANF: In conventional fibres, it is limited by the refractive index of glass, reducing the speed of light in it to ~70% of speed of light in vaccum (Wikipedia on this topic). In this new concept, the light travels 45% faster.
I think, the lower loss (lower attenuation) is "just" an enabler for long distances: You can easily have hundreds of km without repeaters – and repeaters for DNANF cables would add latency. If they can get attenuation improved a bit more, they may even be able to cross the Atlantic ocean without repeaters.
As a nice side effect, those DNANF cables have very little dispersion, so you can get rid of compensating for that, which will reduce latency too.
If this is true (or at least plausible to the relevant people), the author of that Twitter post will probably be on the radar of any shady government agency worldwide. Not a nice situation to be in.
Lots of places in France are so remote and sparsely populated that public transport does not work there, at least not yet. It may or may not work once autonomous vehicles are fit for rural areas, but this may take a while.
From what I've understood, there is a translation table of line thickness to power/speed, that can be configured in the driver.