Is it wise to apply this experience into lighter aircraft as well, as was the original post's topic?
If you're in a similar situation (developing undershoot) then it's worth a try, especially if you're not going to make it if you don't do something. As has been pointed out, most people fly light aircraft around the circuit (and on approach!) considerably faster than the clean stalling speed, so "falling out of the sky" is unlikely.
There are so many variables involved that there's no real hard and fast answer to this particular scenario. There are three basic outcomes: a) flap or no flap, you'll make it b) the right flap setting/speed/trajectory will get you in, the wrong ones won't and c) you're not going to make the airfield, whatever you do. The "approach cone" containing b) is likely to be fairly narrow. It's energy management: you start off with a certain amount of mgh+0.5mv^2 and wish to make the most of it on the way down.
There's speed<->altitude trading, ground effect, wind gradient, airmass motion and a load of other factors. Unsurprisingly, there's no one answer that fits all. If you can see where your trajectory will end and it's not good, then change the configuration; if it's still looking bad then...
What happens when the engine quits is down to workload, experience and currency. There are also external influences such as wind, whether the prop is stopped or not, aircraft weight, etc. What
is important (and stated in the BA38 report) is that if you're going to crash, do it wings level and keep flying the aircraft until the end. As they say, a good approach into a poor area is better than vice-versa. Recognise that you're about to have an accident and make it a
controlled one.