Bit of a 'Boys Book of Aeromodelling' extract you quoted there.....with its references to 'cutting foam wings', 'built up construction' and the astonishing "So if you have a vicious stalling plane on your hands, don't just try to cope till you crash it - add some droops or stall strips - let the plane age gracefully, THEN crash it!"
Incidentally, only non-pilots talk about 'planes'!
Swept wing behaviour at high AoA isn't the same as that of a straight wing - the spanwise flow even before the stall being somewhat more complicated. The heavy jet transport I used to fly also had a stick push system; we used to take it down to the stick shaker during air tests only - but if buffet ever occurred, the exercise was discontinued. AoA probes needed to be carefully set up and the whole system was vital for safe flight. I've had the stick pusher go off on a flapless approach due to incorrect maintenance and faulty 'lift rate modifier' input to the system - quite thought provoking!
The small inboard 'toblerones' on many military trainers were purely there to induce buffet over the elevators at high AoA and had no significant effect on the stall; the devices fitted to the Glasair are totally different in nature, as whatunion states.