I PHPStorm 10 and all previous versions the soft wrap feature would use the right viewport edge as a boundary to break lines. However in PHPStorm 11 it seems the right margin setting is used instead. Considering that the right margin value is static this change in behavior makes PHPStorm absolutely useless for me because I often have the need to resize PHPStorm's window in order to tile it on my 1440p monitors. Now every time I resize PHPStorm half of the lines are either not displayed fully or they don't wrap at all when I set a really high right margin value, which I often do.
I've tried adjusting the right margin value to fit the width I use the most however it quickly turned out to just be a waste of time and I've decided to go back to PHPStorm 10 until the old behavior is restored. And it has to be restored or at least offered as an option because every other editor and IDE out there uses the right viewport edge as a boundary for soft wraps.