⚠️ Metrics mc_tps and mc_tick_duration_* will not be supported because there is no Folia API to get the TPS for a given region/thread (see https://github.com/PaperMC/Folia/issues/31)
Edit: see comments below on how this could be implemented manually.
You can get that information with thread-access in folia-dev. Look at spark implementation of Folia.
I think I found the relevant commit. That's a nice source, thank you.
mc_tpsandmc_tick_duration_*will not be supported because there is no Folia API to get the TPS for a given region/thread (see https://github.com/PaperMC/Folia/issues/31)