Life pro tip: monitor your infrastructure. Screwing around with Grafana is already paying off, I might have identified my first failing SFP+ fiber module. It's still working... but 9mA to transmit -14 dBm over a short fiber run does not match at all with any other modules I have in production and seems very wrong. I'll make sure I have a spare on hand.
Thankfully this is not a mission critical line (no Owncast instances, just a Wi-Fi AP) but nonetheless, I'm already glad I took on this project.