That answers my question, thank you so much.
I had imagined that I could limit the number of shelves to be downloaded to something like 30.
Then if I got the first 30 shelves for 100 books, pretty much all of the purple shelves would be shared and would be trivial to delete with calibre. I would be left with the yellow tags which are more specific.
There's no need for anyone to develop this functionality though. It would have been convenient but I'll be fine without it.
Thanks again for your help!
