No. The old (and new) 80 and EVO 75 are two very different boards, and even 1.5kg weight difference will not erase that difference.
When I read your question again, I think it might be worth trying the Kode 80 after all. Superb high wind performance. In SA you will have nice sideshore conditions, generally, and then it is less demanding to go vertical also in the more traditional type Kode wave board. And in GC the sailing might be more jumping oriented anyway, right? The Kode is developed from the Acid which have been considered on of the best down the line production boards for years _and_ a very good high wind control board. Maybe this is what you're after?