(I don't know if that is a bug or not, but I like this behavior as I *sometimes* want to delete one specific item, rather than merging, and it helps with visualizing the data for the specific item as I navigate via arrow keys. Getting back to "merge view" is still quite easy.)

Yeah, it's by design, since it's one way to select individual items in the Duplicate Items view. But even though it's convenient for the (probably very few) people who know about it, I think we should probably switch to having the arrow keys select the sets instead. That would make keyboard-based access equivalent to mouse usage, which is important for accessibility, and would just generally be less hacky. If you wanted to select a single item, you'd still be able to do it by deselecting item with modifier keys — a little more tedious, but probably a clearer experience overall. (Sorry @enozkan!)

Thank you for the response. I support the idea of a keyboard navigation equivalent for everything that can be done via pointer.