All your 3 questions are related to ucm, if the kernel uses legacy driver, the pulseaudio will work with traditional profile+path (/usr/share/pulesaudio/alsa-mixer/); if the kernel users sof driver, the pulseaudio will work with ucm (/usr/share/alsa/ucm2/sof-hda-dsp/).
The 3 difference you mentioned are introduced by ucm. Maybe we could make the ucm perfect in future, or maybe the latest ucm + pulseaudio already addressed those issues.
All your 3 questions are related to ucm, if the kernel uses legacy driver, the pulseaudio will work with traditional profile+path (/usr/share/ pulesaudio/ alsa-mixer/ ); if the kernel users sof driver, the pulseaudio will work with ucm (/usr/share/ alsa/ucm2/ sof-hda- dsp/).
The 3 difference you mentioned are introduced by ucm. Maybe we could make the ucm perfect in future, or maybe the latest ucm + pulseaudio already addressed those issues.