Set Me Free (In a Far Away Land)

[Mixinthecloud]

I don't care too much about mono compatibility in general, even in my own mixes.
That being said, I was just pointing out that inverting the polarity of one channel of a stereo track is possibly the worst thing that you could do in that regard. I pointed this especially in the context of a commercial mix, because I believe these things still matter today, whether you like it or not.
Not everyone is listening to music in the best possible conditions, one could even argue that more and more people listen on small PC speakers, even laptop or phone speakers (!)... But even with good speakers, not many people stay in the sweet spot, so what they are hearing is mostly mono...
You could say it's their loss, but if you're working in a real world situation where you need to deliver for the vast majority of environments, that's the kind of things to keep an ear on...

I understand your concern and the effect flipping the phase of a single side of a stereo track will do to it when summed in mono. I thank you for your input and will keep it in mind in the future.