For sure after the breed is judged is a great time to talk with the Yorkie exhibitors. Just look at the judging schedule because usually Yorkies are the last breed to be judged in toy breeds, and often times immediately afterward is group judging. For sure exhibitors will not want or have time for questions before breed or before group judging.
Sometimes comformation shows also have some Meet the Breed events, and you can look to see if this is happening by looking at the Premium lists for up coming shows. You can go to
www.akc.org and look up "events" in your State to see what shows are coming, and then click on the the hosting club to find the premium lists. About 7-10 days prior to show start the show superintendents will post the judging schedules which allows you to see what time and in what ring the Yorkies are being judged.