Down/up mix setting in Control Room with Dolby Atmos

I have a perfectly working Dolby Atmos project which I am listening to using my headphones. The down mix setting in the renderer is set to binaural.

I now want to enable the Control Room to be able to switch between a reference stereo track of the same piece and the Dolby Atmos version to finalize the mix. After having switched the audio connection this also works. However what down mix setting to use in the Control Room (CR] for the Atmos mix?

Default CR shows 7.1.4 despite the fact that in the renderer binaural is activated. Should I leave the setting like that, despite using headphones, or should I change it to stereo like you see in some Youtube videos on the subject, There is no binaural option which would have been the obvious choice.

I have the impression that if I change to stereo (you see 7.1.4 > stereo) that I down mix to classical 2.0 stereo and not to binaural.