I do what Steve wrote above, Note to screeners: and yadda yadda..... works everytime, I have had an incident of the comment making it to the db once, thats the negative part of that. But for now we don't have an option untill Johan adds one.
One thing to consider is that the screeners will most likely get a lot of bashing throught the comments? Might be something to think about.
We might be able to use a registration for photographers, lets say a photographer has 20 + photos here, then he has access to the upload page with the Note To Screeners feature? Just an idea.....