When I select a track and hit “z” Cubase will zoom in on the track, which makes it easier to see. That’s the purpose. 
If I press down Shift and hit the down arrow the track below will be selected as well, and now 2 tracks are zoomed.
But if I keep on selecting tracks like that they wont fit the screen any more and I have to scroll down to see the tracks at the bottom.
It would be so nice if Cubase could zoom out automatic so the selected tracks will never zoom more than to fit the screen OR like in Logic where ONLY the first selected track is zoomed in and the following tracks in the selection is “normal” size.
What I would like is a section in Preferences that will allow me to select which kind of zoom-in I want when I expand the selection.