I don't know if it's possible, but if it is, it would be nice for the "damage particles" to not show up through blocks. For instance, I have a mob farm near my home and I keep seeing the numbers pop up even when I'm not anywhere near it.

Seeing damage particles through opaque blocks can be interesting at times, but, yes, overall it seems like a bug. I know we have looked into this before and it certainly is possible. Hopefully we can work this into the next release.

This issue got fixed in this mod with a config option: https://minecraft.curseforge.com/projects/torohud