3 points
This is not so much as an edorsement or recommendation, but you might check out the DAPs by Shanling or Hidiz if you have coin to spare. They use Linux & don’t publish kernel mods, but they do have inexpensive, very small, lightweight options that may fit your needs. I have one & it has a place to have a dedicate device to not chew thru my phone’s battery as well as function as a high-quality USB DAC in scenarios where you don’t have a jack (like my old laptop) or the DAC is horrible (like in my dock for my laptop).