Autographs for popular guests?

Taking my son on Saturday to get a signature from Sean Schemmel, he has Chris Sabbots and would love the pair! Lots have changed since we’ve gone for Autos and the website doesn’t really give much information on this.

1. How do you know when he will be signing?
2. Whaat is a realistic time to be early and ensure we get to his line before an early cap?
3. Where are they held these days within the convention center?

Any help is super appreciated to get to Sean for kiddo ✌️