Updated drivers, still fails. The game loads, it runs in the background, it renders in the background, it plays music in the background. I can alt-tab to it, and its thumbnail preview shows what it is rendering (attached), but it will not take full-screen focus. Attempting to switch to it flashes a couple of black screens as it does its DX device acquisition thing, and then drops back to the desktop where the game continues running in the background.
So at this point the only way I can probably recover, since I've now told the game I want it to render in native 4k and I can't get into the settings to change that, is to completely uninstall and reinstall. I assume the game can't handle the size of this render device, which is kind of bizarre since I don't think 4k * 32bpp is uncommon these days? Then I'd have to drop my desktop resolution below native in order to play it.
New drivers:
[Display]
Operating System: Windows 10 Pro, 64-bit
DirectX version: 12.0
GPU processor: GeForce RTX 2080 SUPER
Driver version: 456.71
Driver Type: DCH
Direct3D API version: 12
Direct3D feature level: 12_1
CUDA Cores: 3072
Core clock: 1815 MHz
Memory data rate: 15.50 Gbps
Memory interface: 256-bit
Memory bandwidth: 496.06 GB/s
Total available graphics memory: 24535 MB
Dedicated video memory: 8192 MB GDDR6
System video memory: 0 MB
Shared system memory: 16343 MB
Video BIOS version: 90.04.7A.00.CD
IRQ: Not used
Bus: PCI Express x16 Gen3
Device Id: 10DE 1E81 30813842
Part Number: G180 0042
[Components]
nvui.dll 8.17.14.5671 NVIDIA User Experience Driver Component
nvxdplcy.dll 8.17.14.5671 NVIDIA User Experience Driver Component
nvxdbat.dll 8.17.14.5671 NVIDIA User Experience Driver Component
nvxdapix.dll 8.17.14.5671 NVIDIA User Experience Driver Component
NVCPL.DLL 8.17.14.5671 NVIDIA User Experience Driver Component
nvCplUIR.dll 8.1.940.0 NVIDIA Control Panel
nvCplUI.exe 8.1.940.0 NVIDIA Control Panel
nvWSSR.dll 27.21.14.5671 NVIDIA Workstation Server
nvWSS.dll 27.21.14.5671 NVIDIA Workstation Server
nvViTvSR.dll 27.21.14.5671 NVIDIA Video Server
nvViTvS.dll 27.21.14.5671 NVIDIA Video Server
nvLicensingS.dll 6.14.14.5671 NVIDIA Licensing Server
nvDevToolSR.dll 27.21.14.5671 NVIDIA Licensing Server
nvDevToolS.dll 27.21.14.5671 NVIDIA 3D Settings Server
nvDispSR.dll 27.21.14.5671 NVIDIA Display Server
nvDispS.dll 27.21.14.5671 NVIDIA Display Server
NVCUDA64.DLL 27.21.14.5671 NVIDIA CUDA 11.1.96 driver
nvGameSR.dll 27.21.14.5671 NVIDIA 3D Settings Server
nvGameS.dll 27.21.14.5671 NVIDIA 3D Settings Server