I don't think that under exposing is being suggested, minimizing might be a better description, or maybe giving up the safety factors.

Flare, like flashing, essential raises the lowest values significantly, easily doubling the density, without moving the highest values much at all, maybe 1%ish, you knew that though I'd bet.

Flare, I theorize, like flashing needs to surpass a threshold point to have a significant effect. Less general exposure can help keep flare/flash exposure under the required threshold and therefore affect the image less.