We had the same experience as Wally on both our trips to CSS.
In fact, I can only remember seeing them once or twice each time we were there. I think maybe the reason they might not be there every day is that not many people use the red flag service at CSS. It really isn't necessary since the bar is, as Wally pointed out, only steps away. But...to answer your question about the food, I have never seen anyone getting food from the red flag staff except when they come around with a tray full of fruit kabobs ( what a great touch!).
I'm not saying they won't...I just never saw it at CSS, CN or CSA.
We have just returned from CSS on July 10th. They had "blue flag" service everyday.
The guy was great. If you were undecided what you want to drink, he had great suggestions.
"Once you go...you know"