There used to be tools to crack apple music DRM, and a lot of it is DRM free now, that’s what I used to get off that eco system a few years ago, and move those files to local files.
No idea if that’s still possible.
Ropiee XL and Volumio both support apple music (uncompressed 44/16), Chromecast (44/16) and DLNA (not sure what the limit on the transport is) that could be used to stream from Apple music, by selecting the output device.
I’m in the treat it like Vinyl camp, buy a $50 Raspberry pi4, install Volumio or Ropieee use the USB directly to the SU-6 and see if you like the difference, possibly buy one of the cheaper Ifi power bricks for it.
If you notice a difference save your pennies and jump in at the deep end.
If you’re not comfortable with installing an OS on a Pi (which is incredibly easy) then buy a Zen Stream, and save your pennies.
I have a Pi2AES I’d sell you, it’s a step up from a basic Pi if you use AES or SPDIF, but like turntables I’m not sure there is a lot of value in messing around in the middle ground.