Critical subwoofer tip

I assume that everyone already knows the importance of phase matching a sub to the main speakers but it’s a little more complicated than simple 90 degrees or 180. The B&W sub that I have has four choices. In every case there has been a definite correct position that can be non standard. My current setup shined at 270 degrees vs the std positions. It’s completely obvious and the other choices would not have been satisfying. 
From my lengthy experience I would want a subwoofer with several phase choices. I personally don’t see how one could seamlessly integrate the mains and the sub without this flexibility. No one asked but i thought this info might be useful to anyone purchasing a subwoofer. YMMV