If this has been raised before, I’m raising it again:
In View > as Tags it would be useful if clicking one or more documents in the list panel at the top of that view caused some visual selection of tags in the righthand panel. Like an asterisk, or boldface/italic, or change the color of the tag bubble. Or, maybe a keystroke would hide all the tags in the righthand panel except the ones that belong to that document or selection.
Something that would make it immediately obvious which tags belong to that document. The tags bar at the bottom of the preview pane can scroll off to the right - often without indicating that more tags exist for that document - and is not very useful for tag browsing in any view.
I think we need better ways to browse tags.