Hi Michael,
For external monitoring, you'll need to use ASIO drivers. I'm using the latest set on the Lynx site (I think it's 15b), but some have used their beta 15c with solid results.
I leave mine at 512 for the cards, 1024 for the VIP.
I recommend opening a project, changing them, then closing out of the project.
There have been times when I thought "saving" the project was enough, only to do something that caused a crash and wiped them out.
It's a PIA for 32 channels.