Comment 1 for bug 70350

A potential problem with using a slider could be fine-grain control on which "previous" or "next" action that you are trying to choose. Also, where would you display this slider?

Another option could be to have an option in "Edit" that lists all Unro/Redo actions in a list and let you choose which one. You could use the up/down buttons to choose. Optionally, you could put the slider in there also.