@bungle linked to a miniDSP app note showing how to set up multichannel surround with the Apple TV 4K and the miniDSP Flex HT/HTx. Apparently the Apple TV 4K can decode various surround formats to multichannel lpcm (although there is no indication in its spec sheet that it can do so). What other devices can do that? My circa 2020 Roku sticks and LG smart TVs cannot. There is no indication on their respective spec pages that the Chromecast or Firestick streamers can do it either. If other streaming devices or TVs do not decode to lpcm, it seems this product has limited applications.