Is there any benefit to this UI pattern of a checkbox toggling a set of radio buttons?
Why not just have 3 radio buttons, always visible? (no / only new / new and existing)
I would have thought that 3 radio buttons would be easier to design and I think they'd be a lot more accessible.
I mean "accessible" in the broadest sense, too. I'm sure it would help users of screen-readers but even those of us who don't use extra tools might be surprised when checking a box reveals further options.