Took a free MQA file from: OPPO Digital - Demo Tracks by DSD Pioneer Musician David Elias
When played, volumio shows the correct encoded information 24/44.1 (as shown in download link)
But the DAC shows the MQA information.
A bit better to read:
In short, Volumio forwards the MQA as is, without any quality loss.
Hopes this makes it more clear.