This is more than a question, it is a request, it would be great if when you enter landscape mode and before creating a terrain as such, in the options you would have the option to create flat or spherical terrain, so as to simulate planets, and be able to sculpt our mountains, create trees and others in it. The only problem would be to create the water or sea so that it adapts to the spherical shape of the planet, for example to the water system plugin (which by the way is still in experimental and the version is still in 0.1…) add a section so that adapts to the shape of the terrain.
Thus, many of us would miss the work of programming or using blueprints so that we can sculpt in it…