Expanding User Meta to work with other post types

I am using a plugin to create multiple tabs in the user profiles. Since these tabs are not on the 'profile' or 'user-edit' pages, any meta_box that has type => 'user' will not render.

Here are the changes so that User Meta will work with other plugins and on any post_type:

File: inc/class-mb-user-meta-box.php

appended add_meta_boxes to the object_hooks function:

protected function object_hooks() {
    ...
    // Allow user meta fields to be used by other plugins and post types.
    add_action( 'add_meta_boxes', array( $this, 'add_meta_boxes' ) );
    ...
}

add a filter to expand valid edit_screens

public function is_edit_screen( $screen = null ) {
    if ( ! is_admin() ) {
        return false;
    }
    $screen = get_current_screen();
    // Allow edit screens to be expanded.
    $edit_screens = apply_filters( 'rwmb_user_edit_screens', array( 'profile', 'user-edit', 'profile-network', 'user-edit-network' ) );
    return in_array( $screen->id, $edit_screens, true );
}

do not limit get_current_user_id to user-edit and profile pages:

public static function get_current_user_id() {
    if ( ! is_admin() ) {
        return false;
    }

    if( !empty( $_REQUEST['user_id'] )){
        return absint( $_REQUEST['user_id'] );
    }
    else if( get_current_user_id() ){
        return get_current_user_id();
    }

    return false;
}

I'll submit a pull request on bitbucket if you like to include these useful changes in a future release.