I'm just curious what your motivation for the patch is, because I too use atuin and see the space-prefix as a feature. It's been around for a while (longer than atuin) to keep certain commands out of my history on purpose, like when running some one-off command with credentials as an arg.

Other than that I very much agree, patching stuff is wonderful in nix-land! Especially when things in nixpkgs-unstable break.