> > So I'm about to try to extract key sub-parts of the bigger parts so that I can try my modifications in no time.
> > I think I could do that with a difference between the big part, and the difference between two cubes (with the inner cube being the volume of the bigger part's sub-part si want to keep).
> Maybe I'm not following, but that sounds like a job for intersection(), not difference().
Yes you're right, I was not crystal clear.
Thanks a lot for your inputs, I have since then made several attempts
with the smallest critical parts sporting my latest changes, and I
noticed a few issues... that will be solved in minutes instead of