Terrain modeling questions

1.) I have a 3D geometry (geolocated import) from Sketchup, but it’s terrible pixelated quality. So it’s the right shape but can’t be sculpted.

I also have the Twinmotion Flat Terrain layer from inside TM itself, which can be sculpted and painted.

So I have 1 “ground layer” that’s the right SHAPE but wrong GRAPHICS, and I have another “ground layer” that’s the WRONG shape but the right graphics.

Is there any way to automatically fit the Twinmotion Terrain to a geometry layer, OR convert a Sketchup geometry layer to this sculptable terrain?

View from “underground”: the Sketchup geometry is on top, the Twinmotion Landscape is below. How can I automatically inflate the TM Landscape up to this?

2.) Is there a way to sharply raise/drop Landscape terrain on a vertical line? Let’s say I have a retaining wall, it’s a 10-foot drop across an 8” depth. The Twinmotion terrain sculpting tool pulls the terrain in a relatively smooth fashion, creating either extra terrain inside a clean 90-degree angle, or if I move it further out, there’s a gap behind the wall.

3.) Is there any way to change the scale of the Landscape sculpting tool to BELOW 1 meter, for fine detail work? Or change the drawing scale, etc?

4.) Is there any way to boundary the terrain changes with a shape or object, i.e. if you want to cut out a precise shape into the ground? Or just set up “masked areas” where the ground would not move?

Aand since “new users can only post one embedded image” (of course, nobody ever has more than 1 question, or needs more than 1 image to illustrate their point, LMAO), here’s a collage…