can you make it so if a player enters a world while vanished, and the player doesn't have permission to be vanished (doesn't have "vanish.vanish" permission) in that world, the player becomes unvanished?

Also, these are permissions that i would like to have on my server:

• vanish.vanish.on (allows "/vanish on")
• vanish.vanish.off (allows "/vanish off")

Your first half already happens with the checkonworldchange setting in config.yml set to true.

Second half, doing for 3.12

Renaming issue from "Unvanish player if he doesn't have vanish permission in world"