It is evident that the problem of tabs passes beyound the limits of graphical capabilities of emacs.
Trying to give a solution for tabs will not bear anything nice -- it would rise a lot of confusion.
To add morphic objects to the actual structure of emacs it is also beyound the limits of the system.
I consider that all the work in the direction of tabs is loss of time.
I would like to open the question whether emacs can be completed with a morphic module .
Having such a structure, emacs will have a main working desktop -- main morph, in which we can drop other kind of morphs -- like buffers, tabs, etc. (the frames will not be useful any more).
I do not consider it is impossible.
But it is bad to invest energy into the actual direction, which is dead.