USB capabilities of lattepanda sigma

Hi,

I have a few questions about compatibility before making a purchase:

Can you confirm that the USB Audio Gadget mode functions properly on these boards? 

Specifically, I'd like to know if an emulated audio device is properly recognized by other devices when connected via USB-C.

I currently use an external GPU connected through USB-C Thunderbolt. Would this external GPU setup be compatible with this device?
 

I appreciate your help in clarifying these technical specifications.

Thanks