Not sure what is the tag-mageddon referred to here; I assume it's a tag change. For me, my use is tag cleanup: I have hundreds of tags accumulated over the years that by now are a clutter, and I intend to remove all tags with low counts, with the obvious tags with 0 notes first, then likely tags with 1 and 2 notes (I'm happy to let the notes remain untagged).
Is there an easy way to delete all these tags? I am on multiple devices, but if I don't care for searching with these tags anymore on any of my devices hence I don't care when it eventually syncs across all devices, is there a quick way to pick all these tags up and delete them rather than manually accumulate them into an aggregate tag to nuke?