15. Does M3K have track quality level icon?

A: Yes, there is a icon indicating the track quality level displaying on the bottom right corner of the M3K's Now playing interface.  

The icon depends on the different sample rate of the tracks:

Lossy format: No icon

Lossless 32kHz and below: No icon

Lossless 44.1kHz and 88.2kHz: SQ

Lossless 96kHz and 384kHz: HR

DSD & iso: DSD