We have been working on improving the experience for players using DX11. While we always suggest using DX12 when possible, DX11 is useful for older graphics cards that don't support DX12 or when avoiding rare Unreal Engine 5.4 incompatibilities with certain AMD processors.
Backrooms Cleanup Crew will give you the option to use DX11 on launch, or optionally in the Properties -> General settings in Steam if you have dismissed the launch options. If you're unsure of which to use, always launch regularly first and see if your experience is stable - only if experiencing very low framerate do we suggest launching DX11.
Fixed a few issues when playing on DX11 with very low framerates in certain areas such as the Wasteland in 3-03
Fixed a few issues when playing on DX11 with severe sunlight bleed in areas such as the D-Force lobby in levels with sunlight
Fixed issues when playing on DX11 where certain areas would look drastically too bright or too dark