What GPU do you use? AMD and NVIDIA use drastically different methods to encode, though they should look the same at the end, it would help us troubleshoot to know more about your host system.

I can confirm that black levels are being crushed using steam link with Quest 3. I have a Nvidia card RTX 2080 and intel i7 9700k. I noticed it in Walkabout golf on darker levels. Details in dark areas in native quest version are visible but using steam link with pc version, those same areas have crushed blacks, cannot see any detail.

Could the problem here be that steam is encoding the full range color 0-255 and then converted to limited range? or something like that. Really hope this can be addressed soon. Steam link is otherwise fantastic.

same here

can confirm that dark scenes are extremely dark when using steam link. 3080ti, tried both HEVC and h.264. headset is Quest 3

I had this same issue with Virtual Desktop - and I was able to fix it this way, maybe it'll help you out here?

Simply go into windows display settings, advanced display, turn off automatically manage color for apps.

in your quest settings under accessibility > vision turn contrast all the way down