Hi Mike.
You're right, only 1 undo, if you're lucky.
(That's not always guarenteed to work)
This issue has been brought up before, and has been addressed for the next release.
I was frustrated about this when I started using it also, but I don't even notice it any more.
Creating geometry, toolpaths etc is fairly easy and quick, so the undo really isn't an issue.
'Rekd