If you google something like "latex rivers" or "latex microtype river" then you will see that there have been discussions, and some attempts. (Perhaps the issu

If you google something like "latex rivers" or "latex microtype river" then you will see that there have been discussions, and some attempts. (Perhaps the issue is not as pronounced for mathematics, because of authors shying away from overly long paragraphs and because displayed equations break up paragraphs?)