I was experimenting much with different ways to render shadows/rams/fog (even dynamic shadows that change depending on their position relative to point of view), and I agree that ramp rendering could be better. I like how it looks, but ramps (both up and down) are effectively belong to the lower level - creature can't stand on a downramp. So they should be rendered as such. But now I feel it's taking too long already and I will try to release it as soon as possible as is, then we'll see.
Multilevel and twbt will still be the single plugin (currently with twbt itself, overrides, multilevel and a command to save full map image) for performance and organisational reasons - they all hook the same renderer methods and share some code.