I've searched and searched and I still cannot find where you get the new subscreen with all the new item spaces and such. I'm using Version 2.10
New Items
This would be a question for the ZQuest Editor Help forum, so I'll just be moving this over there.
Go to Quest-->Master Subscreen Type --> Revision 2. That should do it.
That's looking at the recent betas too, but it should be similar, if not identical to 2.10.
Naw, in 2.10 its in Quest --> Misc. Data --> Subscreen Type