Clever solution. Heh Heh I think you might be able to do it with the pan and crop feature. I have used it to rotate scenes for effects and, if I understand the help file correctly (never easy with Vegas) you can do what you are thinking of with it, too.
Congratulations on a clever solution. I have personally created rather long credits with credit roll by just adding more lines, easy to do in that mode.
I wish there was a way to directly enter a value for duration the way you can in other editors. Sony doesn't take suggestions from users very seriously, so I doubt this feature will ever be added.
If freedom means anything at all, it is the liberty to tell others what they don't want to hear.