OS: Linux, Mint 20 Cinnamon 4.6.7. QCAD 3.27.8
An observation:
In: QCAD.org Forum - Information, Andrew implied that Alt-click would bring up a context menu to allow selection of overlapping lines. In practice, I find it necessary to do Ctrl-Alt-click. This leads to a further small problem: to select multiple segments it is necessary to hold down the , and at the same time (a slow operation on my standard keyboard) in order to choose the next overlapping segment.
If an improvement were possible I’d love to see repeated ‘Alt-click’-ing cycle through selecting the various overlapping lines.