https://bugs.winehq.org/show_bug.cgi?id=55597
--- Comment #1 from stephematician@gmail.com --- Looks like this was a case of the incorrect graphics card being used. Running via:
__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia wine Planet\ Of\ Lana.exe
resolved the slowdown on the second display (it seems). I did not need `__VK_LAYER_NV_optimus=NVIDIA_only` as I don't believe DXVK is used by the application.
A separate bug, perhaps, but I also tested with `winehg-staging` package (8.15), and I found that the main laptop screen (regardless of PRIME render offload settings) would become corrupted when I exited the program. This did not occur with `winehq-stable` (8.02) so there's a possible regression.