What happened?

From what I could gather, this is said to be implemented in the old repository in this issue, but I can't make it work.

Was this removed at some point or is it a bug?

BetterNether

9.0.10

BCLib

3.0.14

Fabric API

0.92.2

Fabric Loader

0.16.3

Minecraft

1.20.1

Relevant log output

Other Mods

Lots of other mods, will list if necessary