I have read nowhere - nor felt any difference - in FW/RW bias with Sport/ Sport+.
Mapping of gearbox changes when in Sport/Sport+ - so does throttle respons.
My reading of Sport vs Sport+ is "slackened" ESP i.e. the aggressive interference from ESP will go away and you can have fun driving on snow/ice!
Dynamic Damper Control has its own life - stiff activated in Sport/Sport+