I ran across a Youtube video for tag.properties that sounds like what this thread is calling Supertags. It adds properties to a note when the note is tagged.
The author says it is only a few dozen lines of code so maybe someone could turn it into a plugin?
I wish this was the kind of “Template” feature that Obsidian bult-in plugin had, where template would be more granular and add both a set of properties and sections from the presence or absence of tags.
Prefilled sections would allow for dataview content being automatically added to some kinds of pages.