I suggest that these commands be modified to allow for more things to be undone and redone. For instance, if I close a tab by accident and decide I want it back, I have to waste time typing in the name of the resource in the command box to summon it again because the undo command won't reopen a deleted tab. This can be especially troublesome with unfamiliar resources that I may not remember the name of for whatever reason. Being able to do quick "command+z" and "command+shift+z" keyboard shortcuts (Mac user) would especially helpful. And these seem like such simple, time saving features to have left out of the software. I don't see any reason why features like these have not been better implemented.