I am trying to find another solution as an Amazon HD Ultra user. I am looking for end point devices that can be used both for Roon and Amazon. The closest I have found right now is the BluSound Node 2i which can support playing Amazon playlists and be a Roon end point that can be controlled by the Roon App. The BlueSound app on my phone enables both. This is a similar approach Bose took on their end point. Support connections to multiple music service. Found out Roon can use those as endpoint through AirPlay I think which is not the best quality but at least allows you to connect. Also found that the BlueSound can access all the music ripped for Roon that is sitting on my file server even without Roon. A very nice device that enables you to also use a very high quality DAC if you want.
With testing have shown that Amazon HD play at 44.1/16bit and HD Ultra play as high as 192/24b.
The DAC connected to my BlueSound is reporting that bit rate being played through it. Also confirmed that files Roon has and 192 play as expected though the Bluesound at 192. Just an FYi