I wrote the RenoDX mod if you're talking about that. I don't think there's anything like Reshade's addon system for Linux games. We've done OpenGL and Vulkan mods but that still relies on intercepting the Windows implementation. Silksong primarily needs a 16bit float render to solve most of its banding, but not sure how you can do the same on Linux.
We avoid per-game executable patching intentionally, but sounds like that would be the best choice here. Getting the render to 16bit would solve most banding, but you'd still need to replace shaders if your goal were HDR (or fake it as a postprocess with something like vkBasalt).