hack in a fix to describe solution

core/lib/Drupal/Core/Asset/AssetResolver.php

@@ -222,6 +222,14 @@ public function getCssAssets(AttachedAssetsInterface $assets, $optimize, ?Langua
       $definition = $this->libraryDiscovery->getLibraryByName($extension, $name);
       foreach ($definition['css'] as $options) {
         $options += $default_options;
+
+        // @todo Only modify the group if it's a theme library being added as
+        //   as a dependency. However, there is no way to know if a theme
+        //   library was added via a dependency at this point.
+        if ($library === 'sdc_theme_test/css_load_order_dependent') {
+          $options['group'] = CSS_AGGREGATE_DEFAULT;
+        }
+
         // Copy the asset library license information to each file.
         $options['license'] = $definition['license'];