An imported STEP file is converted to a triangle mesh on import (making it much like a typical .stl or .3mf file) which means that slicing all happens as one would normally expect.

I want to do some very basic editing of STEP files, e.g.: Read in two or three STEP files, align the components with respect to two faces or two axes, and save Read in a STEP file, delete a few ...

The most common reason an STL file may be not quite right is a mechanical connection where some piece isn’t quite as the designer expected, so the 3D model that interfaces with it no longer fits.