Closeup view of the bottom side of the Main PCB

DSP Group - DS18B - Audio DSP

Maxim Audio Amplifier - most likely MAX98502

ST Micro - STM32L431RC6 - MCU

Unknown component. Labelled "ix6". Please leave a comment if you happen to know this component

Programming Interface and test points. Looks to be the standard ARM 20 Pin connector layout.

Bluetooth Antenna. Runs around the outside of the Main PCB - Top and Bottom