If you do a search for "undo" in the Idea Exchange, you'll find a litany of suggestions and requests for improvements.
Some probably require some major refactoring of the LabVIEW code, so we better forget about them (mine included).
But no undo in the "Description and Tip" window?
Or the (Control/Indicator) Properties window?
Or (an old one) in the VI Properties window (from 3 years ago)?
Or the Shortcut Menu Editor window?
Etc, etc...
Suggestion: Implement a full-fledged Undo/Copy/Cut/Paste in all these windows.
This is a missing basic productivity tool.