When is someone in charge of such things for an OS vendor going to realize that for any of "my" documents, what I really want is to tag them?
I would jettison every piece of computing hardware I own right now and switch to the first device that would let me add (and search) tags in file metadata.
xattr -s author George file
(It might need a -w, I'm not sure as I'm writing it with my iPad)
I'm not sure it's searchable though.
But unless I'm very mistaken, mdls (metadata list) Is searchable. It lists what's been saved by Spotlight and you can add to it.