I have been trying to a lot of landscaping since its was added as a feature. Unfortunately, it seems to have some bugs.

It doesn't do flat right. I've torn down mountains and filled in ditches, but many times it says that the land isn't flat. Making it flat so I could use the area was the whole point. Its real annoying when you try to put down a big dome but I can't find a flat enough area.

Landscaping nanites creates a mess. They leave rocks all over the place. They will not use designated storage areas if I provide them. Not only that, but they've put rocks in areas that is unreachable for my rovers and drones. This does not stop my drones from trying reach them to clean up. I've had to reduce the range of a drone hub on at least one occasion to prevent the drones from wasting their time. It has also prevented me from doing more landscaping as you have to clean up the mess before any work can be done.

I have also been annoyed that the Flatten landscaping doesn't always get usably "flat" from first-pass landscaping.

What I have discovered is this.
A first pass Flatten project usually gets the swath flat enough that you can run pipes and cables through it. It also seems to expand the trully flat area that you started from a bit. The edges and far end of the swath in particular may need to be re-worked.
A 2nd, or even 3rd pass, repositioned to start from the bit of area the DID get really flat, may be necessary to get an area flat enough to build a dome. I've taken to checking the "flatness" of a landscape area with a basic dome build "ghost" to find the portions that need more scraping.
A Dozer seems to get an area flatter, sooner than just drones.
If you need to flatten a large area that requires multiple "swaths" of landscaping, to assure the smoothness needed for a large dome, etc, you will need to either:
- overlap the landscaping swaths ~50%, or
- run tight parallel swaths (convenient since you can lay them all down at once), but then make a 2nd pass where you scrape the "seams" between the original swaths.
Check the smoothed area with a basic dome construction "ghost". You may need to spot flatten a few spots.

I guess I have not encountered the landscaping nanites yet. I don't find the small heaps of leftover stone left by drones and dozer to be much problem because the build mechanic does not treat them as blocking objects, just suface clutter that the building drones have to move in the early stages of construction, like some surface stones.

Some other points about landscaping.
Ramps up to major plateau areas are a) cool, b) are surprisingly quick for a dozer to build, c) unlike tunnels, cannot be smashed by meteors.
Ramps slanted at an angle across the face of an escarpment seem to work best. I think they require less filling / fill material.
Ramps into otherwise difficult to access craters (usually with beaucoup water) are real nice, but you do have to be careful to start them well back from the crater edge, so the slope is gentle and pipe / cable compatible as soon as finished, and you don't have to keep re scuplting.
Using Flatten to connect 2 nearby craters that both have 2-3 water sites in the bottom is just Cool!. But it can take a long time.
Having default Ramp width set as wider than default Flatten width is jst kinda nuts to me. And why not have it adjustable, like the control radii?

I have not yet been able to figure out any practical use for the Soil Texturing feature. Unless someone can explain an undiscovered use to me, I have to assume that it is just cosmetic. And who has time for that?