Starting point is where you press the mouse button, ending point is where you release the mouse button after moving it over the desired lane. With this move you mark the area of the lane which is activated then. Very easy to correct and very easy to mark different areas on different lanes. Maybe have a look at YouTube's video's on Cubase comping approach when it firstly came up (I think around Cubase 7 or 7.5).
Thanks a lot deadman42 ! I will try this. Sounds indeed like it is a more efficient way to select from the recorded takes 😁.