Exactly my thoughts.
After three years of desperately trying to make supfoiling work on a DW board (i'm flatwater based and i only can practise this at my holiday trips) and looking at the younger and/or more athletic (or skilled) guys supfoiling i was about to quit this attempt (also after waisting a lot of money in different iDW boards and foils). But these old (and cheap) "soapbar" shapes seem to be another spark of hope for me to maybe learning supfoiling one day, despite only being able to practise it in my holidays.
When i tried it years ago i did use the oldschool thick and low aspect foils like Moses 873 or Slingshot Infinity 84. Would it help to try it now with modern foils like a KT Atlas 1340 or Nomad 1160 or are these modern wings not a good match for such old shapes?