Was having the same issue, got it working with Redmi Note 4 snapdragon (mido) on MIUI 9 Nougat after researching a bit
and found out that you should edit build prop and change this:
ro.product.manufacturer=samsung
and add this line:
persist.audio.uhqa=1
Hi res output works flawlessly, but it will say that it use Samsung UHQA DAC.
Also got it working on my Meizu Pro 5 with beta nougat firmware 6.8.1.8A, although the app purchase sync was broken and it will eventually showed that the license have expired.