Left handed service for Certified Service Exam

I am a strong left handed server, hold the try with my right hand, and old habits die hard.  Is it more important to be comfortable and just focus on keeping my body language as open as possible in Certified service portion of the exam or suffer a potential slip of champagne glasses and attempt to hold the tray in my opposite hand in keeping with court standards?  I have a friend who dropped glasses and failed service once for this and DID pass by being a left hander.   I have my exam in the next week and am very curious if anyone thinks this is JUDGED HARSHLY...?