we'd like to refine the undo implemented in MPS. Here's the problem: when deleting a node, we do some additional AST changes. Thus, we need to press ctrl/cmd-z many times to get back to the initial state. However, the developer should be allowed just pressing once and then getting back to the initial state (as internal AST changes are hidden from the developer and thus he shouldn't concern about them).
Is there an easy way to achieve that objective?