When I launch a Guest OS, I am prompted to provide access for each of my connected USB devices to the Guest. Options provided are "Allow, Deny, and Always Allow." In many cases what I'd actually like to do is "Always Deny," because I am NEVER going to want to use that peripheral in that OS (and the fact that it periodically gets "accidentally claimed" by the Guest interferes with other desktop operations. Of course, you can provide an admin panel where you could revert such decisions. But this single change would be a major improvement in convenience for me.