Shouldn't this load the rlist isntead? see: https://github.com/redCOMPONENT-COM/redCORE/blob/develop/libraries/redcore/form/fields/rchildlist.php#L12 and https://github.com/redCOMPONENT-COM/redCORE/blob/develop/libraries/redcore/form/fields/rchildlist.php#L21