That is correct.

It looks to me like it doesnt break out if you cant edit the parent, it just doesnt add the link so it will skip that level of the breadcrumb. It might be better if it added it to the breadcrumb with a show link (assuming you have show permissions) or just no link at all (somewhat of defeats the purpose of a breadcrumb although its still informational).

I will add a max recursion parameter to the menu configuration. How about menu_node_admin_max_breadcrumb_level with a default of 5. Could also be a menu_node_admin top level array key with a max_breadcrumb_level child scalar.

Unless you feel that refactoring to the RouteProvider example would be worthwhile I will leave as is since I believe the end result is the same.