ReShade and Duckststion Vulkan/DirectX switching

For testing purposes I switch Duckstation between Vulkan and DX11/12.

ReShade has to be installed each time with correct API for it's injection to work.

C:\ProgramData\ReShade\ReShadeApps.ini has the added entry for Duckstation (self-generated).

OTOH RetroArch for example also has Vulkan and DX11/12, and it is enough to re-launch the program after swapping and the hooks will work - ReShade was installed once as DX11/12 (dxgi.dll).

Note that I've tried rendering to a separate window and over Duckstation itself, and fullscreen vs windowed.

Is this expected?

This is expected, hooking Vulkan/OpenGL works very differently. For Vulkan ReShade is loaded via the Vulkan layering mechanism from C:\ProgramData\ReShade, for OpenGL ReShade is loaded via DLL wrapping and thus needs to be placed as opengl32.dll in the application directory. As such switching to OpenGL requires one to recreate the opengl32.dll in the app directory, while switching to Vulkan needs that removed (which is why reinstallation takes care of).