Undo feature/keyboard shortcut - Critical Feature Request

This is a critical feature that my team has run into several times. When highlighting several tasks to get a scope of hours, if there is a change made, it affects ALL of the tasks selected. And this could be hundreds of tasks. Our recommendation is to create a keyboard shortcut for “undo”. We see that there is a copy and paste feature, but it is critical to include a cntl+z or cmd+z. Many times if we click away from the highlighted items, we have to go back and update each individual task. PLEASE HELP!