I looked at the schematics of the PDM amplifier chips linke and I am puzzled why they put a DAC in front of a class d amp. Can you just digitally amplify the PDM out and then do the low pass trick. I thought that was all the class-d amps are doing.
I guess you can't really trust the raw PDM output from an MCU which might not be very well designed or shaped.
Maybe better to convert back to analog and then apply whatever secret sauce you have to make the class D amplifier work really well.
Here’s a white paper of his specifically about direct PWM amplification.
https://www.researchgate.net/publication/242013327_All_ampli...