Our customer has an installation with between 10,000 and 100,000 assets.
The tree view is ok. but the author can't be used really because everything that leans on the list view does not work.
For the assets app this is the list view, the thumbnail view and the search.
What also happens that when you use one of those functions is they time out but stay in the Vaadin session.
So when you try to get in again it restarts the active view, which times out so you are effectively locked out.
You can use another browser or incognito-window to avoid this.