Option: added active desktop option which allows kde to be primary desktop environment.

system/desktop/default.nix

@@ -21,8 +21,20 @@ in {
     enable = mkEO "enable desktop related programs (+home manager).";
     apps = mkEO "extra bloat.";
     games = mkEO "gaming related programs";
+
     hyprland = mkEO "enable hyprland related programs.";
     kde = mkEO "enable kde specialisation.";
+    activeDesktop = lib.mkOption {
+      type = lib.types.enum ["hyprland" "kde"];
+      description = "What desktop should be the default, other enabled desktops will be specialized.";
+      default =
+        if cfg.hyprland
+        then "hyprland"
+        else if cfg.kde
+        then "kde"
+        else "hyprland";
+      example = "hyprland";
+    };
   };
 
   config.assertions = mkIf (cfg.hyprland

system/desktop/greetd.nix

@@ -5,21 +5,9 @@
 }: {
   config = lib.mkIf config.niksos.desktop.enable {
     # greetd display manager
-    services.greetd = let
-      session = {
-        command = lib.mkDefault "${lib.getExe config.programs.uwsm.package} start hyprland-uwsm.desktop";
-        user = "jsw";
-      };
-    in {
+    services.greetd = {
       enable = true;
-
-      settings = {
-        terminal.vt = 1;
-        default_session = session;
-        initial_session = session;
-      };
+      settings.terminal.vt = 1;
     };
-
-    programs.uwsm.enable = config.niksos.desktop.hyprland;
   };
 }

system/desktop/hyprland.nix

@@ -1,16 +1,37 @@
 {
-  config,
-  pkgs,
   lib,
+  pkgs,
+  config,
   ...
 }: let
-  cfg = config.niksos.desktop.enable && config.niksos.desktop.hyprland;
+  inherit (config.niksos) desktop;
+  cfg = desktop.enable && desktop.hyprland;
+  active = cfg && desktop.activeDesktop == "hyprland";
+  ifActive = x: lib.mkIf active x;
 in {
-  config = lib.mkIf cfg {
-    programs.hyprland = {
+  specialisation.hyprland.configuration =
+    lib.mkIf cfg
+    && !active {
+      niksos.desktop.activeDesktop = lib.mkForce "hyprland";
+    };
+
+  programs = ifActive {
+    hyprland = {
       enable = true;
       withUWSM = true;
     };
-    environment.sessionVariables.NIXOS_OZONE_WL = "1"; # Makes electron apps use wayland.
+    uwsm.enable = true;
   };
+
+  services.greetd.settings = let
+    session = {
+      command = "${lib.getExe config.programs.uwsm.package} start hyprland-uwsm.desktop";
+      user = "jsw";
+    };
+  in
+    ifActive {
+      default_session = session;
+      initial_session = session;
+    };
+  environment.sessionVariables.NIXOS_OZONE_WL = ifActive "1"; # Makes electron apps use wayland.
 }

system/desktop/plasma6.nix

@@ -4,25 +4,28 @@
   config,
   ...
 }: let
-  cfg = config.niksos.desktop.enable && config.niksos.desktop.kde;
+  inherit (config.niksos) desktop;
+  cfg = desktop.enable && desktop.kde;
+  active = cfg && desktop.activeDesktop == "kde";
+  ifActive = x: lib.mkIf active x;
 in {
-  specialisation.de.configuration = lib.mkIf cfg {
-    niksos.desktop.hyprland = lib.mkForce false;
-    services = {
-      greetd = let
-        session.command = "${pkgs.kdePackages.plasma-workspace}/bin/startplasma-wayland";
-      in {
-        enable = true;
-        settings = {
-          terminal.vt = 1;
-          default_session = session;
-          initial_session = session;
-        };
-      };
-
-      desktopManager.plasma6.enable = true;
+  specialisation.kde.configuration =
+    lib.mkIf cfg
+    && !active {
+      niksos.desktop.activeDesktop = lib.mkForce "kde";
     };
 
-    home-manager.users.jsw.stylix.autoEnable = false;
+  services = ifActive {
+    greetd.settings = let
+      session.command = "${pkgs.kdePackages.plasma-workspace}/bin/startplasma-wayland";
+    in {
+      default_session = session;
+      initial_session = session;
+    };
+
+    desktopManager.plasma6.enable = true;
+  };
+  home-manager.users = ifActive {
+    jsw.stylix.autoEnable = false;
   };
 }

system/desktop/polkit.nix

@@ -3,10 +3,8 @@
   lib,
   pkgs,
   ...
-}: let
-  cfg = config.niksos.desktop.enable && config.niksos.desktop.hyprland;
-in {
-  systemd.user.services.polkit-gnome-authentication-agent-1 = lib.mkIf cfg {
+}: {
+  systemd.user.services.polkit-gnome-authentication-agent-1 = lib.mkIf config.programs.hyprland.enable {
     description = "polkit-gnome-authentication-agent-1";
     wantedBy = ["graphical-session.target"];
     wants = ["graphical-session.target"];

system/desktop/xdg.nix

@@ -3,10 +3,8 @@
   config,
   lib,
   ...
-}: let
-  cfg = config.niksos.desktop.enable && config.niksos.desktop.hyprland;
-in {
-  xdg.portal = lib.mkIf cfg {
+}: {
+  xdg.portal = lib.mkIf config.programs.hyprland.enable {
     enable = true;
     xdgOpenUsePortal = true;
     config = {