

Attached there is the current version. Consecutive Exectution is removed - TrackWidget replaces it with the benefit of a better user interface and better integration into QCad. You'll need at least QCad 3.7.2 because I'm using setGroupOrder, or you have to remove the call in each script (just search for "action.setGroupSortOrder(QCTrack.MenuOrder.GroupSortOrder);" and remove the entire line).
The track widget integrates itself into the Widget panel. Now just select the desired track from the track widget and start extension of an existing track by typing QN or selecting "Insert new track from track widget". Mouse over the existing track and you'll get a preview of the track that would be inserted by left mouse click. If you want to change the connection end, you may right-click in the track widget, click on the "rotate button", select "Rotate track at track widget" or - most preferrable - just enter QR (will work even with mouse over a track, so you see the result "on line"). I will post an updated tutorial later.
Thank you Andrew for your support, and thank you Husky for inciting me to give TrackWidget yet another try.