I was also there (should have checked for a topic like this in advance) and boy was it a blast. My first such event. I didn't make any recordings but I jotted down some recollections right after the fact.
- His intro lecture on the development of Korean writing was fun and while I knew that MaiPon and Forgery were inspired by his time there, I didn't realize he had also based the Aons on the way Korean writing works as well.
- Someone in the crowd asked what Copper compounding does during the QA session. He didn't answer specifically but mentioned that not all compounding does neat things, just most forms. Apparently copper isn't one of them.
- When he signed my books, he included the phrase 'Hands all red...'. Other people I talked to got the same thing.
- I asked about Chromium's ability to affect other forms of Investiture (ie leeching Breath or Stormlight) and got RAFO'd, followed by a general statement that most magics have cross-world effects, like Bronze sensing other forms of Investiture but we already knew about that. I suppose I should have expected that response for a crossover question but hey, now I'm part of the RAFO club.