Thank you.
My WP Customize have some filters so you can same customize to apply to all sites.
e.g.)
add_filter( 'mywp_controller_admin_sidebar_get_sidebar' , 'custom_mywp_controller_admin_sidebar_get_sidebar' );
function custom_mywp_controller_admin_sidebar_get_sidebar( $posts ) {
$defaults = array(
'ID' => '',
'post_author' => 1,
'menu_order' => 0,
'post_parent' => 0,
'item_parent' => 0,
'item_type' => 'default',
'item_default_type' => '',
'item_default_id' => '',
'item_default_parent_id' => '',
'item_capability' => '',
'item_li_class' => '',
'item_li_id' => '',
'item_link_class' => '',
'item_link_id' => '',
'item_link_title' => '',
'item_link_url' => '',
'item_link_attr' => '',
'item_icon_class' => '',
'item_icon_id' => '',
'item_icon_class' => '',
'item_icon_title' => '',
'item_icon_style' => '',
'item_icon_img' => '',
);
$sidebar_items = array();
$sidebar_items[] = (object) wp_parse_args(
array(
'ID' => 'menu-dashboard',
'item_default_type' => 'menu',
'item_default_id' => 'index.php',
'item_default_parent_id' => '',
'item_link_title' => 'Dashboard',
'item_icon_class' => 'dashicons-before dashicons-dashboard',
),
$defaults
);
return $sidebar_items;
}