I added this digital download release:
.. to an existing almost-the-right-thing release-group. However, I'm having second thoughts now. The (release) artist is Lena Katina, but that's not what the release group is listed under (Dave Audé feat. Lena Katina), so I suspect that the prior release/group is actually a remix-re-release.
I don't know what to do, now. Should they be different release groups? Should the release-group artist change, and then the “feat” only apply to the remix release?