Help modifying existing package (Spacevim)

I’ve been using Spacevim for a while. Tough I’d be happy to look into other options, it’s easy to setup and edit. However, I’ve not been able to add other plugins or options to the package.

I’ve gotten pretty close, but the edits aren’t showing… Any help with this would be appreciated.

The following link shows how spacevim_config is loaded:
spacevim_config ? import ./init.nix

Here is the init.nix file:

This makes me think I can declare it elsewhere… (right?)

So I am loading spacevim on my configuration.nix file under environment.systemsPackages:

environment.systemPackages = with pkgs; [
  devenv
  direnv
  php83Packages.php-codesniffer
  spacevim
  wget
  wmutils-core
  wp-cli
];

Then lower down on the same file I am attempting to load spacevim_config from a file. Hoping to set it before the “default” nix.init file is:

nixpkgs.config = {
  spacevim_config = import ../../modNixos/programs/spacevim.nix;
};

This is my slightly modified spacevim.nix version of nix.init:

{
  custom_plugins = [
    {
      merged = false;
      name = "lilydjwg/colorizer";
    }
    {
      name = "vim-vdebug/vdebug";
      port = 9003;
    }
  ];
  layers = [
    { name = "default"; }
    {
      enable = true;
      name = "colorscheme";
    }
    { name = "fzf"; }
    {
      default_height = 30;
      default_position = "top";
      name = "shell";
    }
    { name = "edit"; }
    { name = "VersionControl"; }
    { name = "git"; }
    {
      auto-completion-return-key-behavior = "complete";
      auto-completion-tab-key-behavior = "cycle";
      autocomplete_method = "coc";
      name = "autocomplete";
    }
    { name = "lang#ruby"; }
    { name = "lang#nix"; }
    { name = "lang#java"; }
    { name = "lang#kotlin"; }
    { name = "lang#sh"; }
    { name = "lang#html"; }
    { name = "lang#php"; }
  ];
  options = {
    buffer_index_type = 4;
    colorscheme = "gruvbox";
    colorscheme_bg = "dark";
    enable_guicolors = true;
    enable_statusline_mode = true;
    enable_tabline_filetype_icon = true;
    statusline_separator = "fire";
    timeoutlen = 500;
    relativenumber = false;
  };
}

However the file does not seem to be used/loaded. What am I doing wrong? I’d love to be able to add plugins and config setting to spacevim.