ALL tags view, categorised, drag to attach
This is actually still relying on human memeory. If I have more than about 30 -50 tags I can't remember them all. So I'll miss some attaching to files and the system is weakened.
Make a pane open on one click showing ALL tags created. Best to enable categories (headers or folders). Select MULTIPLE Tags as desired - Drag to file (or select and click file.
I'm afraid without this Tags are of limited use if I have to keep to only 30 or else accept that many files do not have their relevant Tags.