You might want to reverse that order
Your existing tagging can exist while working on your new paradigm
It’s so easy to delete existing tags
Using the Tags group; select and delete
retrospect, mindless tagging
My tagging process is controlled using an applescript
The first tag is a note type; for example !Type-Receipt
This drives additional tags, for example !Vendor and !Budget
I reflect hierarchy in my tag names; for example !Budget, !Budget-Housing, !Budget-HousingRent
I avoid “orphan” tags