I will repeat my question, why would a class-D amplifier care about phase angle.I’ll repeat my answer in another way, negative phase angle combined with low impedance can as in the Alexia, gives a EPDR of load as seen by the amp of 0.9ohm load!!!!
Now you go find a Class-D that will keep pushing even more current into that kind of loading like a good bi-polar amp can.
If you can hear it at a shop with speakers like the Alexia you'll be stunned at what just a good 100w bi-polar amp like Gryphon v any Class-D of any wattage, the Gryphon will be superior at those EPDR frequencies in the bass.
Cheers George