I would love to see a plugin that allows quick, mass edits, where conditions can be matched and various actions can be taken. Something like an advanced batch rename tool.
For instance, after opening up a prompt, a user could select all files with a certain tag, and then change a certain YAML attribute within that file. Search + Dataview + MetaEdit.
This would be very useful for tracking dynamic objects, like people or characters. Also very applicable to TTRPG management.