Tweaking OneSignal WordPress Plugin

/**
 * Send push based on last active time (Intelligent Delivery).
 */
add_filter( 'onesignal_send_notification', function( $fields ) {
    $fields['delayed_option'] = 'last-active';

    return $fields;
});

/**
 * Always set notification unchecked in post editor.
 */
add_filter( 'onesignal_meta_box_send_notification_checkbox_state', '__return_false' );

/**
 * Disable onesignal in every pages except posts.
 */
add_action( 'template_redirect', function() {
    if ( ! is_single() ) {
        remove_action( 'wp_head', array( 'OneSignal_Public', 'onesignal_header' ) );
    }
});