Adapters, YEAH.
This is exactly the kind of thing I need on a larger scale; I implore you to make adapters for the largest sizes of modter, and consider getting steep grade into the mix.
So far I've found one brick (or type of brick) which I think is missing from this pack:
Inside corner adapters
Green: half-grade ("4x") slope
Blue: 45-degree ("2x") slope
Purple: "4x to 2x Adapter R"
Orange: "4x slant+ inv 1/2h"
Cyan: Non-existent adapter which is needed to make a smooth transition (Imagine driving downhill in this corner and hitting those orange bricks)