Centaurus, those tools have their limitations. The Macchis had them on the side wall, and in about 1978, when a canopy was to be removed by maintenance and discarded, the Powers decided it would be good to do a real test on the tool. All the staff and students gathered around, and the steely-eyed knuck walked to the aircraft.
The pilot was strapped in the front seat, the lid was closed and locked, and the clock started.
It was a weird feeling, watching somebody deliberately hacking at the canopy from inside, but what was surprising was that the canopy didn't break easily. It took him a LOT of backhanded hacking, then a rest of the tired arms, a change of grip and more hacking until a tiny hole appeared. A lot more hacking and he managed to make a hole big enough to squeeze out of, and the clock showed over 8 minutes. He was exhausted and overheated. A fire might have heated him a bit too much during the 8 minutes.
We all formed new opinions on the strength of the canopy, and the usefulness of the tool.