Does Angular work with a VDOM? If it manages it’s own VDOM then it might just consider the element empty and not destroy it when diffing. Elm pretty reliably does this. In fact I usually use empty element like div[][] to bind non elm libraries like text editors etc.
Also, I don’t know what happens to a
Browser.elementif some external JS removes the DOM element that it’s “controlling” - does it crash, gracefully terminate itself, hang around in memory, updating an element tree that’s not actually inwindow.documentanymore.
We were just discussing that here 
Basically… No it doesn’t gracefully clean itself up.