Config.php

<?php

namespace GMJ\Foobar;

class Config extends \ArrayObject {}

Plugin.php

<?php

namespace GMJ\Foobar;

class Plugin {
	function run() {
		$shortcode_config    = new Config( include DT_EIA_DIR . 'config/shortcode.php', \ArrayObject::ARRAY_AS_PROPS );
		$shortcodeui_config  = new Config( include DT_EIA_DIR . 'config/shortcodeui.php', \ArrayObject::ARRAY_AS_PROPS );
		$dependencies_config = new Config( include DT_EIA_DIR . 'config/dependencies.php', \ArrayObject::ARRAY_AS_PROPS );

		$dependencies = new Dependencies( $dependencies_config );
		$shortcode    = new Shortcode( $shortcode_config, new Shortcode_Atts_Parser, $dependencies );
		$shortcodeui  = new ShortcodeUI( $shortcodeui_config, $shortcode_config->shortcode_tag );

		add_action( 'init', [ $shortcode, 'register' ] );
		add_action( 'init', [ $shortcodeui, 'register' ] );
		add_action( 'wp_enqueue_scripts', [ $dependencies, 'register' ] );
		add_action( 'admin_enqueue_scripts', [ $dependencies, 'register' ] );
		add_action( 'shortcode_ui_before_do_shortcode', array( $dependencies, 'admin_output' ) );
	}
}

Shortcodes.php

<?php

namespace GMJ\Foobar;

class Shortcode {
	protected $config;

	function __construct( Config $config ) { // minimal example
		$this->config = $config;
	}

	function tag() {
		return $this->config->shortcode_tag;
	}
	
	// ...
}

Hey Gary,

In DT\EIA\Plugin, add use GMJ\Foobar to bring the class Config into scope.