It would be incredibly useful to be able to visualize biome borders.
I just started making a river-biome drowned farm with a friend and looked for a Fabric-equivalent of Biome Border Viewer and found none. Seems like it would fit well into minihud.

Looks like this was added in 0.21.2, thanks!

This feature is on the todo list for MiniHUD. But unfortunately my todo list is very long, and since main development still happens in 1.12.2, it will additionally take a long time for new features to arrive to the versions of the mod for the later MC versions...

Ok, well good to hear it's on the list anyways.