If you have to call ahead and ask, you have really outed yourself. Even stating that a friend raved about that server, it would be a red flag. Chances are, the target is NOT a star at all, so your claim would be very suspect.
That said, I have had hotel shops with a ton of required interactions, were there were requests to seek out and interact with (or avoid) a particular server at a coffee counter/bake shop/deli counter and to try particular shifts to find or avoid that person. Sometimes that works; other times....nah. BUT, an explanation of what happened when that was not possible has always been accepted.
Based in MD, near DC
Shopping from the Carolinas to New York
Have video cam; will travel
Poor customer service? Don't get mad; get video.