My first time setup of HDR took longer than it needed. Since the enable toggle is in player settings, I was confused if I can see HDR in editor or only in player builds. I understand some of it was my fault but do think if we add some clarity to the docs it will be easier for our users.
I suggest in section "Enabling HDR Output" to mention that HDR is supported in player builds and in editor Game view(only).
In this page: https://docs.unity3d.com/Packages/com.unity.render-pipelines.high-definition@15.0/manual/HDR-Output.html