It's reasonable to trim these facets (in previous examples, I did that by hand in SketchUp). The most obvious choice is to define the boundary box (picture 2) and remove all the facets which intersect with it.
Now, I can generate new objects and preview them in SketchUp (picture 6) really quickly.
The next candidates for automatic processing are the "spikes", which still remain on the object, but somehow do not belong to it.





