We do not have the fully automated workflow solution in our account Andrzej Belka. This would be the only reason for upgrading which I find a bit costly. The Solution Bob Miller mentions do not work either for us.

We want the option to keep the proof locked for guests while the user can add to the comments. We are using the set action functionality to filter the "done" comments and have to unlock. While we do this the customer can add comments to done items which we will not see.