Add increased line spacing during widow/orphan protection?

[Oakwine]

It might look nice if you stretched out the line spacing when you have moved widow or orphan lines to adjacent pages, so that a middle-of-a-chapter page still extends all the way to the bottom of the screen.

[nicoverbruggen]

Going to close this here and refer you to #56 which is a similar request. I like the idea, but in practice it's difficult due to engine constraints. We'll see what's possible.