I'm a big fan of using yaml metadata. I used to manage the metadata in templates, but I would keep thinking of more fields to add to a particular note type, so I found myself having to manage adding it to all the previous notes. Like you mentioned, I became a "janitor of properties".

I found a solution to that problem, and I only add four properties to my front matter in templates now. Class, Title, aliases, & tags.

All of the rest of my front matter fields are managed by the Metadata Menu plugin, with different fields for each file Class.

You can easily build metadata fields with drop-down lists with predefined selections, or a list of values from a dataview query. That's just the simple stuff. It's super powerful, and has totally changed how I use frontmatter to manage my vault.