I've noticed that my M1 MBP provides a seemingly implausible degree of stereo width (the left and right channel sound as if they are at a physically more extrem

I've noticed that my M1 MBP provides a seemingly implausible degree of stereo width (the left and right channel sound as if they are at a physically more extreme angle relative to your head than they actually are) but only if you are in the right place relative to the laptop. Also, if you play a pure R tone, you will hear it in the L speaker (wlog). This leads me to suspect they are doing some phasing tricks to increase the perception of stereo (again, assuming you're in the right place relative to the laptop).