+1 on the Grace Digital Link. It's a very good streamer for the price. Amazon (U)HD has been a bit confusing on what it is streaming. I've tried connecting my old Note 8 using USB output to my dac and bit rate is limited similar to the Grace Link. 24/44. In the Grace+ app, I see MPEG4-ACC is being sent.
I can Chromecast Qobuz to the Link with 16/44 (CD Quality) and sounds very good. I have to listen harder to hear the difference with AMHD. I've been trying to use 24/96 in Qobuz but not sure if it's my dac, Qobuz, or the Link causing the stutterring/static sound. Grace Digital says it's not their device. Qobuz says to increase the app cache to prevent stuttering. The manufacturer of my dac is a bit responsive being an EU company.
All in all, I would still recommend the Grace Link. My next step would be to get a Raspberry Pi 4 since I've read that the usb out has significant improvement over the rpi3 where I wouldn't need the Allo Digione stack card.
I know in our hobby, 1's and 0's are bit different for us but working in IT I can't seem to spend the money on a $2k-4k streamer even though my DAC is $3k. These new streamers are mini computers so I think a rpi4 would be just as good esepecially since I can use Roon or Volumio.