I thought the DPLL setting was tied to the sabre chipset firmware, so the only thing needed is for the firmware/display to show it, I don't see how MQA/USB chipset has anything to do with it.
But i, and many others who have the non-MQA version would appreciate it if it was possible to add it but I understand if it's impossible thanks anyway!
I would like to report the requirement to our engineers. Thank you!
By the way, the DPLL setting do in the Sabre chip, but it's not only displayed in the setting menu. Also, high DPLL bandwidth mode may reduce the sound quality.