Wing boards are normally shorter, thinner and with less volume than Sup boards. The shapes themselves have also morphed and differentiated now somewhat.

Yes foils differentiate for different disciplines although there is a definitely an overlap and certain foils that peeps use for all disciplines - although the size may alter. Bigger for Sup than for say winging. There are specialised downwind foils for sure.

The new midlength boards from varying brands are affording some cross over for sure. But like anything - if you try and cover too many bases you end up doing nothing nothing really well. Always a compromise - foil and board choice.