Thanks for this great mod!

Playing around with it locally (dev branch and stuff) and ran into sand-3 (at least) not being fully interchangeable with landfill in that you cannot pave over it.

Is this intentional for some of the custom landfill variants?

Looks like the following can't take pavement:
local terrains = {
"dry-dirt",
"dirt-4",
"grass-1",
"red-desert-1",
"sand-3",
}

The more I think about it, the more I think this is a 2.0 only problem with the changes to how landfill works and the dev2.0 branch. Feel free to ignore if it's already in-progress!