aleskrejci

> (…) nobody else seems to be making an opposing claim.

Did you skip the first comment of this thread?

Hold Option and double-click the window corner. This will probably do what you want (fill all of the available space). You can also do this with the sides of the window and have it grow only horizontally or vertically.

I would also recommend trying out if BetterTouchTool can't change the behaviour of the green (+) button as it's pretty powerful.