Longer answer:
He said he has lots of things in his head the problem was getting his hands to reproduce the image in his head the way he imagines them. Often they end up locking quite different and that can be frustrating.
I also asked Isaac how much freedom he gets from Brandon for the maps and symbols and so on.
A: He gets a lot of freedom with the maps. There were actually times they changed parts of the books to fit the maps.
Q: I asked after an example
A: They changed around directions in the Kholinar chapters a lot.
Q: And the glyphs and other symbols?
A: For the glyphs he has a symmetry tool which he played around a lot with. They developed the glyphs later in full from those images they liked
For the allomantic symbols he had a couple different ideas which didn't seem to work well. Then he had an idea about a bunch of nails lying around haphazardly and from that image the allomantic symbols evolved.
I also talked a bit with Isaac about Germany since he has lived here before. So apparantly he likes our bread and our castles.
I also asked Brandon if he had read the new War of the spark novel, especially Davriels Cameo in it. He said he hadn't gotten around to reading it but would like to. But Wizards sent him the part with Davriels Cameo. So without spoilering sth for those who haven't read the novel: He thinks what Davriel does is very typical for him.
The way he is described is because he is in disguise but if you could hear his inner voice he would be constantly complaining. I regreted that we didn't get to hear his thoughts.
All answers are heavily paraphrased.
There are also two more Wobs thanks to @The Forumlurker who posted them in the other thread to the german signings.
1. If a radiant tried to soulcast using stormlight directly from the highstorm what essences could they create?
A: Anything. They could create any essence. This is for radiant soulcasters not soulcasting fabrials.
2. Could a windrunner only lash part of something, like only a hand instead of an entire body?
A: This is theoretically possible. It’s like how Kelsier can push on a pole and make it spin. This would require a lot of skill however. But yes it is possible