Stig, I'm sure you already know this but the '2 finger' braking comes from riding your bike with your first two fingers on the brake lever (at all times) and your thumb, ring and pinkie fingers gripping the throttle. That way you can activate the front brake in a split second or even better, you can light up your brake light any time you let up on the throttle to warn those behind you.
The braking difference comes in the short time it would take you to remove all 4 fingers from the throttle to grab the lever vs always having 2 fingers on the lever. At higher speeds the extra 20-50 (?) feet shorter stopping distance could very well save your life. With small hands it's hard to do this without adjustable levers.
Well Jim, (bear with me - this week daughter & I must call everyone Jim, incl. ea. other
*
I never ride with 2 fingers on the lever.
I think I might have years ago - but my first winter riding with the bulk of battery heated liners under thick leather gauntlets made that a non starter for my leisurely rides out on country roads.
At 19°F, using no screen - I have to keep things simple.
Every time I tried (years ago) it felt too awkward. Now I just ride with 4-on-the-floor, so to speak.
I was periodically lighting all my rear LEDs on the foggy/foggy ride home the other day. To illuminate me presence!
But I just did it with the weakest brake, the rear, which hardly slows the scoot.
However, you make a very good case for riding with 2 fingers in one position and 3 in another. I hope people take your advice.
Major Jim
* Last week it was "Steve"