Domain mapping Cross-domain autologin

Hello, when the "Cross-domain autologin" is deactivated will the user be logged in to the mainsite?

I'm wondering what happens to buddypress and network activity tracking network wide comments and blog posts when the "Cross-domain autologin" is deactivated?

Without testing it seems deactivating the cross-domain autologin is the way to go, but I still hope that network activity would be tracked in real-time and also show up in my buddypress activity stream.