I would like to propose to remove the "can't be redone" requester. Or at least make it not block the soft untill you click it away. A simple sound effect to tell you you're at the and of your redo's should be enough, eventually combined with a small visual glitch. Or at least give us the option to turn it off. (Maybe this is already possible, and I didn't find it. In that case this whole remove feature request is obsolete)
Undo and redo is, at least in my case, and my guess is that I'm not alone here, a feature that's used A LOT. And almost every time I bump into this requester to be clicked away before continuing. Every time it breaks my workflow, and today is the day it bugs me this much I decided to write this request.