Hopefully you have all your nix configs backed up somewhere? 😅
those configs get added to the nix files, not sure how I leverage that include directive in such an environment.
Ah yeah, I'm guessing you don't? I don't really know anything about nix yet so I don't understand how it can combine keyboard shortcuts for different shells and Niri into one Niri config other than if you add them manually. I feel like keyboard shortcuts are a very personal thing.
Especially it you're running a custom keyboard like me with Colemak-DH layout. Then the default keyboard shortcuts will most likely not be great. 😅