WP MU plugin to force WP-SCSS plugin to run with desired settings, which can be changed in this file when you download it for installation.

scss-compile.php

<?php
/**
 * Plugin Name:     SCSS Compile
 * Description:     Makes sure SCSS compilation is ready.
 * Author:          Tenseg LLC
 * Author URI:      https://www.tenseg.net
 * Text Domain:     tg-scss-compile
 * Version:         1.0.0
 *
 * @package         tg-scss-compile
 */

class TG_SCSS_Compile {
	/**
	 * Settings
	 *
	 * @var array of settings
	 */
	private $settings = [
		'base_compiling_folder' => 'Child Theme',
		'scss_dir' => '/assets/scss/',
		'css_dir' => '/assets/css/',
		'compiling_options' => 'expanded',
		'sourcemap_options' => 'SOURCE_MAP_INLINE',
		'errors' => 'show',
	];

	/**
	 * Class constructor
	 */
	public function __construct() {
		add_action( 'plugins_loaded', [$this, 'scss_compiler_loader'] );
		add_filter( 'plugin_action_links', [$this, 'disable_plugin_actions'], 10, 4 );
		add_filter( 'default_option_wpscss_options', [$this, 'force_scss_settings'], 10, 2 );
		add_filter( 'option_wpscss_options', [$this, 'force_scss_settings'], 10, 2 );
	}

	/**
	 * Forces the SCSS Compiler to be on.
	 *
	 * Called by action: plugins_loaded
	 *
	 * @return void
	 */
	public function scss_compiler_loader() {
		// check for the toolkit
		if ( file_exists( WP_PLUGIN_DIR . '/wp-scss/wp-scss.php' ) ) {
			require_once WP_PLUGIN_DIR . '/wp-scss/wp-scss.php';
		} else {
			add_action( 'admin_notices', function () {
				echo "<div class='error'><p>Please install WP-SCSS plugin.</p></div>";
			} );
		}
	}

	/**
	 * Turn off plugin actions for the toolkit.
	 *
	 * @param array $actions
	 * @param string $plugin_file
	 * @param array $plugin_data
	 * @param string $context
	 * @return array
	 */
	public function disable_plugin_actions( $actions, $plugin_file, $plugin_data, $context ) {
		if ( str_starts_with( $plugin_file, 'wp-scss' ) ) {
			return [];
		}
		return $actions;
	}

	/**
	 * Force the SCSS settings.
	 *
	 * Called by filter: option_pmpro_gateway_environment
	 * Called by filter: default_option_pmpro_gateway_environment
	 *
	 * @param mixed $value the option's value
	 * @param string $option the option's name
	 * @return mixed the option's value
	 */
	function force_scss_settings( $value, $option ) {
		return $this->settings;
	}
}

$tg_scss_compile = new TG_SCSS_Compile();