Thank you, I just saw that yesterday thanks to optimism.
I found also this one which is archived:
https://github.com/0xB10C/bitcoind-observer

And this:
https://github.com/AltaModaTech/btcnode-metrics/tree/main

And although it is not pluggable to Prometheus I found this one using Phoenix (Erlang) which can be good to take a look at what others do without Grafana:
https://github.com/151henry151/node-probe/tree/main