Halo: Campaign evolved. HDR fix until a RenoDX mod comes out.

[VirtuaTyKing]

Settings with liliums shaders.
In game peak max 2000
My game reads about 1506 peak brightness still!

Liliums black floor fix
Gamma adjustment setting
BT.709
Gamma 1.223
Processing cut off 1506 nits

Liliums tone mapping
BT.2446 method A
800 target
Static tone mapping 1506 max

Adjust according to your displays peak nits.
Natively the HDR is terrible but I was pretty happy how it looked after this. Seemed to fix the black floor issue and colour doesn't look washed out.