Flags for note values aren't shown, if there are tuplet-changes (lute tablature)

I think that there should be automatically shown a flag, if there is a change between triplets and eights. Now it isn't, what doesn't really make sense in my opinion, as in such a case definitely the note value is changing, even if tuplet numbers are not displayed (as it is per default now).
Currently one can force a flag to be shown by changing the beam properties, but that will also changed a linked notation voice, which then shouldn't be.
In my opinion the flags always should shown so to say parallel to the automatic beam beginnings!
(also for 3.0-dev)