When adding two text overlays (probably all other types as well; one bottom left, one bottom right) by using a layouter a shadow is displayed in the background too far away. I asume, that the shadow doesn't consider the calculated overlay position (see ).
Then when removing the overlays and adding them again (for a wizard like workflow) the layouter calculates the new position at the wrong place. It rises in y direction. So when you keep on removing and adding the overlay continues rising y direction.
Looking onto the code  I think that the calculation of the position is wrong.
Case Bottom left either considers the bounds of the bottom right one in y direction or it considers the already deleted overlay.
So I will position my overlays manually.
A feature request: additional layout positions middle left and right would be benificial.
 mitk::Overlay2DLayouter::PrepareLayout() ln 184 ff.