In case anyone comes across this, this is what vkBasalt does. Rough overview:

1. Install vkBasalt
2. Download shaders and put them somewhere
   • The vkBasalt readme links to one example, I used the ones here instead: https://github.com/gripped/vkBasalt-working-reshade-shaders/tree/master/allshaders/reshade-shaders-working/
3. Configure vkBasalt
   • There's a sample config in the vkBasalt repo. It took me a bit of trial and error to get working but there are GUI tools too apparently like https://github.com/benjamimgois/goverlay
   • Since you mentioned saturation specifically, here's my minimum config for saturation:

     # Define which effects to load
     effects = vibrance
     
     # Map effect name to full shader path
     vibrance = /home/user/.local/share/vkBasalt/shaders/Vibrance.fx
     
     # Explicitly tell vkBasalt where ReShade includes live
     reshadeIncludePath = /home/user/.local/share/vkBasalt/shaders
     
     # Increase saturation
     Vibrance = 0.5
     

     • You'll also need to define reshadeTexturePath if you end up downloading anything in the Textures directories from any of the shader repos
4. Run the game with ENABLE_VKBASALT=1
   • If you're playing in Steam you can modify the game's launch properties, e.g. ENABLE_VKBASALT=1 %command%