I'm quickly reminded of Photoshop's "History" window and how it was one of my first adds to the standard environment setup to make it visually prominent in the top right of the workspace. You could quickly click up/down it and view the steps, but the functionality is in the end the same as undo/redo, where you lose the others once you make a change after walking backwards.

I can't imagine it would be too crazy for IDE's to begin to add the same, per file at first but maybe also per project and then with saving some of those trees.