Oh that's really interesting.This is inside Yoshi JP on the Snap inis. Didn't test canvaswidth.
[Render]
bForce720P = 1
ClipLeft = 4
ClipTop = 4
ClipRight = 4
ClipBottom = 4
CanvasWidth = 600
ConstValue0 = 0x800fcbe3
ConstValue1 = 0x800fc0b5 ;scene switch
ConstValue2 = 0x8020c0d7 ;secen switch in pot
ConstValue3 = 0x8020c0e7 ; push in pot == 0x18
Could you try CanvasWidth = 1280?