The second option you provided worked out the best for me, so thanks for that, I really appreciate it! The third one didn't let me add more than 2 tags; not sure it was supposed to or not.
One more question for you though regarding that formula:
Code:
{#status:}{:'uppercase(list_item(list_intersection(field("tag"),sublist("Mystery,Science Fiction",0,0,","), ","),0,","))'| - |}
Is there any way to just leave the field empty if there is no matching tag? IE - no "read status" value added to the column if there are no tags found; it just remains completely blank. It's only 2 extra shelves created (all read books and all unread books), so not a huge a deal if that can't be done.
Thanks