Borderlands 3 - HDR Optimized Settings
Added 2022-03-15 15:31:55 +0000 UTC
The game is NOT using/applying Xbox/Playstation HDR Calibration app settings.
The game has a fairly good HDR implementation with a proper Peak HDR Brightness slider in nits (up to 1.000 nits) + a dedicated sliders for UI Luminance.

If you have an LG OLED and:
> you're using Dynamic Tone Mapping or Dynamic Contrast:
Set Max Brightness (Nits) slider to: 1.000 (nits; Max)
> you're using HGIG:
Set Max Brightness (Nits) slider to: 800 (nits) or 1.000 (for G2/C4/G3/G4)
If you don't have an LG OLED and:
> you don't have an HGIG option:
Set Max Brightness (Nits) slider to: 1.000 (nits);
> you're using HGIG:
Set Max Brightness (Nits) slider the corresponding real Peak HDR Luminance of your TV in "nits" (up to 1.000 nits max)
In all cases leave the "UI Brightness" slider to: Default or increase the UI luminance to your tastes.