wait, why is undoing by word better? I like backbone's approach!
Native behavior for comparison. React is following it; Backbone is not. The native behavior on macOS, for instance, undoes all three words in one action: https://imgur.com/a/jKl5exU
(Not your fault: most people misremember this...)
This is why you should always be wary about re-implementing OS behaviour yourself in your widgets, you will always miss at least one detail, but more probably dozens of them.