Seems like I can't put any other sprites anywhere. Even on a different layout.
But the "player" sprite seems to have no effect, Tried adding the sprite first then the mode 7 affected sprite... same result..
It's weirdly not "spritesheet aware" so the only way to make it work for me is to set the maximum sprite sheet size to 512 and make the floor that size (or make the max whatever the floor size is).