Issues when group tag and ordinary tag with the same name exist

I am making a transition from an indexed & folder-based approach to a pure tag-based approach. (I have previously posted about this here and here.)
During the transition, I have items in groups, functioning as group tags, and items tagged with ordinary tags.

There is also a case where I have groups representing status, one of which being called “Reading” - to indicate that something is being read - and an ordinary tag called Reading, used to tag items about the topic of “Reading”.