Exactly what I was looking for. Great.
It is especially wrong in the current core code to show the tag selection box when there are no tags for a user to select from for a category. The last code solves this UX problem. It should be in core this way @team
In addition, there should be two standard texts for the tag selection drop-down:
“optional tags”
and one if tags are mandatory (and available for a user) for a category
“select at least X tags”