Nintendo DS has 2 screens : Screen A and Screen B
Desmume can :
Screen A : 2xBRZ, 3xBRZ, 4xBRZ, 5xBRZ,...
Screen B : normal
More game just one screen, screen 2 only to selected icon
==> can reduce CPU consumption
Sorry, I bad eng !
don't hold your breath. use x432r for that kind of thing.