https://en.wikipedia.org/wiki/Puck_of_Pook%27s_Hill#Original_illustrations
The last line (at most widths) is much taller than the others, which is
aesthetically ugly.
I honestly cannot think of any case where having the lines be different
heights would be preferable. I could see not using the full width available
to even out multiple lines, but not making one line much larger.
This mode is meant to replace the old mode, but such unaesthetic behaviour
would make this impractical.
-Adam