[Support request] Automatic excerpt on protected content

Hello,

It’s possible to automatically add the excerpt on all PROTECTED articles?
Instead of doing it manually with the MORE tag?

on class-wp-members.php i have seen that there is a function

	/**
	 * Creates an excerpt on the fly if there is no 'more' tag.
	 *
	 * @since 2.6
	 * @since 3.2.3 Moved to WP_Members class.
	 * @since 3.2.5 Check if post object exists.
	 *
	 * @global object $post  The post object.
	 * @global object $wpmem The WP_Members object.
	 *
	 * @param  string $content
	 * @return string $content
	 */
	function do_excerpt( $content ) {

that seems undocumented. The only way you suggest is manually using the MORE tag.

Any advice?
Thanks