Import whole directories in sites yaml files
Symfony itself supports importing whole folders with this syntax: https://symfony.com/blog/new-in-symfony-3-3-import-config-files-with-glob-patterns
but since TYPO3 has its own implementation around it in \TYPO3\CMS\Core\Configuration\Loader\YamlFileLoader::loadAndParse, this is not supported.
This would be super helpful in multisite environments with shared configs with having multiple route enhancers that are automatically imported when adding a new one instead of defining them all manually like so:
config - shared - routeEnhancers - routerEnhancer1.yaml - routerEnhancer2.yaml - routerEnhancer2.yaml - index.yaml (imports: 'routeEnhancers/') - sites - website1 - config.yaml (imports: '../../shared/Index.yaml')