Once we are in a new window e.g. with Panels-all selected + Edit new window
displays only panels from the file.
I find very useful if it be possible to select only between the displayed elements by clicking on the "structural axis"
Actually if an axis is selected, (in the New Window) all the elements and nodes (from the file belonging to this axis) are selected regardless if those are "absent" or not.
If the selection is only of the displayed elements, those elements can be handled easily.