In case you weren’t aware, different DS games assume different blank values between the two screens (when they are oriented top/bottom). For instance Metroid Prime Pinball seems to want a pixel gap of about 48 pixels. Other games like Contra 4, Sonic Rush etc. need different values to look correct and have sprites move properly and predictably from one screen to the other.
I’ve spent some time googling but haven’t found anywhere that has compiled a list of these values. Is anyone aware of such a list? It’s a bit time-consuming to figure out each one manually.