if you are using more than one finger with disk brakes, something is amiss..
I don’t think this is true. Just something made up by the mags (and others).
I’ve been riding since the old calliper brakes and it took 2 fingers to stop, so 2 fingers just naturally go on the brake levers. From v-brakes to discs, still 2 fingers. I can make a conscious effort to use 1 finger, but it makes not a jot of difference.
However I’ve just orders new XTs and the lever is only long enough for 1 fingered braking, so my brain will probably re-train my fingers.