diff --git a/flake.nix b/flake.nix
index 96a0973..e62c252 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,17 +3,17 @@
 
   nixConfig = {
     extra-substituters = [
-      "https://cache.rgbcu.be/"
       "https://cache.garnix.io/"
       "https://cache.privatevoid.net"
+      "https://cache.rgbcu.be/"
       "https://hyprland.cachix.org/"
       "https://nix-community.cachix.org/"
     ];
 
     extra-trusted-public-keys = [
-      "cache.rgbcu.be:nBN/5Qg5E8GIYwaoslm9DYo2zeqlBiCVNCPf17djr+w="
       "cache.garnix.io:CTFPyKSLcx5RMJKfLo5EEPUObbA78b0YQ2DTCJXqr9g="
       "cache.privatevoid.net:SErQ8bvNWANeAvtsOESUwVYr2VJynfuc9JRwlzTTkVg="
+      "cache.rgbcu.be:nBN/5Qg5E8GIYwaoslm9DYo2zeqlBiCVNCPf17djr+w="
       "hyprland.cachix.org-1:a7pgxzMz7+chwVL3/pzj6jIBMioiJM7ypFP8PwtkuGc="
       "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
     ];
diff --git a/modules/common/helix.nix b/modules/common/helix.nix
index edc08eb..d13e06f 100644
--- a/modules/common/helix.nix
+++ b/modules/common/helix.nix
@@ -209,7 +209,7 @@ in {
       lua-language-server
 
       # MARKDOWN
-      markdown-oxide
+      marksman
 
       # NIX
       nixfmt-rfc-style
diff --git a/modules/common/nix.nix b/modules/common/nix.nix
index a5ca627..bc60bb7 100644
--- a/modules/common/nix.nix
+++ b/modules/common/nix.nix
@@ -42,14 +42,14 @@ in {
     |> mapAttrs (_: flake: { inherit flake; });
 
   nix.settings = (import <| self + /flake.nix).nixConfig
-    |> flip removeAttrs (optionals config.isDarwin [ "use-cgroups" ]);
-    # |> (if config.isLinux && config.services.nix-serve.enable then
-    #   (cfg: cfg // {
-    #     extra-substituters = cfg.extra-substituters
-    #       |> filter (x: match ".*cache.rgbcu.be.*" x == null);
-    #   })
-    # else
-    #   id);
+    |> flip removeAttrs (optionals config.isDarwin [ "use-cgroups" ])
+    |> (if config.isLinux && config.services.nix-serve.enable then
+      (cfg: cfg // {
+        extra-substituters = cfg.extra-substituters
+          |> filter (x: match ".*cache.rgbcu.be.*" x != null);
+      })
+    else
+      id);
 
   nix.optimise.automatic = true;
 
diff --git a/modules/common/nushell/default.nix b/modules/common/nushell/default.nix
index 8e8005a..c36f193 100644
--- a/modules/common/nushell/default.nix
+++ b/modules/common/nushell/default.nix
@@ -57,11 +57,6 @@ in {
         inherit (self.starship) src;
         hash = "sha256-nH1iYjKw/GbYKadoymH3onWBbMzuMUaRCSTNWVE+A9E=";
       };
-
-      nativeBuildInputs = old.nativeBuildInputs ++ [
-        pkgs.cmake
-        pkgs.zlib-ng
-      ];
     });
   })];
 
diff --git a/modules/darwin/paperwm.nix b/modules/darwin/paperwm.nix
index bff5a14..070f035 100644
--- a/modules/darwin/paperwm.nix
+++ b/modules/darwin/paperwm.nix
@@ -18,7 +18,7 @@ in {
     NSScrollAnimationEnabled = true;
     NSWindowResizeTime       = 0.001;
 
-    "com.apple.keyboard.fnState" = false; # Don't invert Fn.
+    # "com.apple.keyboard.fnState" = true; # Invert Fn.
     "com.apple.trackpad.scaling" = 1.5;  # Faster mouse speed.
 
     InitialKeyRepeat             = 15;
diff --git a/modules/linux/kernel.nix b/modules/linux/kernel.nix
index 50976d1..0ca1079 100644
--- a/modules/linux/kernel.nix
+++ b/modules/linux/kernel.nix
@@ -1,8 +1,5 @@
-{ config, pkgs, ... }: {
-  boot.kernelPackages = if config.isServer then
-    pkgs.linuxPackages_latest
-  else
-    pkgs.linuxKernel.packages.linux_zen;
+{ pkgs, ... }: {
+  boot.kernelPackages = pkgs.linuxPackages_latest;
 
   # Credits:
   # - https://github.com/NotAShelf/nyx/blob/main/modules/core/common/system/security/kernel.nix