Thanks.
I'm surprised Superstar Saga doesn't support the C-Stick for the map. Paper Jam did. I kept the map off the screen as much as possible (and even if I did use it I'd use touch) so I haven't tried despite finishing the game!
I suspect Culdcept Revolt might. Either it's very well programmed or it's doing 60fps in 3D mode at all times which is very rare for a 3DS title, especially one that uses the GPU's fixed function shaders a lot.
I had a look around on gamefaqs and apparently Metroid: Samus Returns operates at a locked 30fps on N3DS, but has dips on original 3DSes. Given it uses similar tech to Castlevania: Mirror of Fate on 3DS, I can believe that. But it needs to be verified.
Lastly, I reckon Fire Emblem Echoes is N3DS-enhanced. From what I played I remember it having superior antialiasing to previous games, and I can't see that being the case on the original 3DS. I would test this but I no longer have my original 3DS...