If we are talking about in-ceiling speakers, ditch the idea of stereo altogether. No one does serious listening with speakers like that. They’re only for background music.
If that isn’t convincing, “stereo” only works if you’re in the “sweet spot” dead-center between the two speakers. Who’s going to take the trouble to stand in the right location?
Again, this is a background music system. Just go with mono at all locations.
Regards,
Wayne A. Pflughaupt