Menu Depth > 1 not shown for users for user without permission 'show administration menu in the toolbar'

Problem/Motivation

If a user/role (other than uid 1) don't have the permission 'show administration menu in the toolbar', nested menus do not work.
The top level is rendered, but sub levels are not visible.

@see: https://www.drupal.org/project/toolbar_menu/issues/2949053#comment-12681327

Steps to reproduce

1. Install toolbar_menu and toolbar_menu_clean modules
2. Create a nested menu with toolbar_menu to replace "administration menu" for a specific role
3. Give the permission to see your new menu (toolbar_menu) and remove permission 'show administration menu in the toolbar' (toolbar_menu_clean)

Proposed resolution

As suggested in this issue for the toolbar_menu module, change the line 36 in toolbar_menu_clean.module file :

unset($items['administration'])
by
$items['administration']['#wrapper_attributes']['class'] = 'visually-hidden';

Merge toolbar_menu and toolbar_menu_clean ?

I discover the toolbar_menu_clean project from this issue on toolbar_menu project. Clearly, toolbar_menu_clean is an important complement to toolbar_menu to provide a good "editor" or "webmaster" experience ! IMHO, 2 project are related and thing will be easier if it was only one project (maybe with a submodule).