Just want to warn you that switching to Compatibility mode can cause a flashing white line to appear at the top of the screen, so if anyone reports that issue, that's probably the cause.
Good to know, thank you!
OPP runs on compatibility mode and no-one reported such, so I hope that persists. The only reason I wasn’t using Compatibility mode at the start was it needed to be Forward+ instead to use Volumetric Fog, but I discovered I was overthinking it and could just set a sharp min and max distance away from the player with regular fog.