thanks for your hint, it is not quite the same as I described but comes
quite close. A cut performed this way still leaves a lot of room to
manually clean up, what is ok, but it would be better if there existed a
more high level semantic of "change active track".
BTW re crash course - unfortunately the manual does not show any results
with the search term "multicam" - it is really just because it is sunday
that I can take the time and have patience to investigate about how these
basic things work in Kdenlive going to the mailing list, what is an unusual
high effort to gain knowledge.