So after trying I can say that Steam Link is literally the same as a Remote Play, it even has the same settings and everything… But on Desktop mode the Remote Play works so much better for whatever reason. Both HEVC and HW-decoding also work.

However when HW-decoding is enabled all the colors are washed out and blacks are just medium grays (more white-ish than black) for example so all of the main OLED advantages are lost. Same happens if I enable HW encoding on my PC side, in which case I have the same issue with HW decoding enabled/disabled on Steam Deck side.

Now that may be because of RDNA2 encoder but since this happens also when just decoding when the source is CPU encoded, idk for sure.

Now the issue is that in desktop mode I’m locked to 90Hz so I’m forced to stream 90FPS otherwise the gameplay is not smooth as it would be at 60Hz so I lose some visual advantage from HEVC in trade for smoothness… Guess I can’t have it all unless there is some way to force 60Hz on desktop?