Open the gallery (Tools | Gallery) and start ZoomText with magnification larger
than 1.  Make the item view in the lower right of the gallery larger than the
magnifiers view port.

When the selection in the item view changes then ZoomText moves the magnifier so
that the left or top side of the item view is aligned with the left or top side
of the magnification view port.
This is done regardless of whether the selected item is in the view port or not,
i.e. is off the right or bottom side.  The bounding boxes of the items are
correct but seem to be ignored by ZoomText.