FOSS gamedev and creative worlds

I was recently working on my ethereal mod when I thought it would be nice to have layers of fillers on different levels. For example
G = Grass
D = Dirt
F = Sandstone.

GGGGG
DDDDD
FFFFFF

Do you understand my meaning? If so could this be implemented.

Yes, i do this a lot in my paragen mod to create rock strata, however i believe the MGV7 lua biome api may only be able to do one filler type. For multiple layers it helps to use 3D perlin noise mapgen, as this creates a 'density' noise that can be used to vary the thickness of all the layers (see paragen screenshots).