The other option would be a longer prone surf, it can be still much lighter than a SUP, especially in the nose for the swing weight.
Something like:
www.gong-galaxy.com/en/magazine/news-en/gear-carter-foil-eps/The 7'3" should be a good compromise.
I am not saying that you should buy a Gong model, it is just as an example.
Plus learning some paddleboard techniques to prone paddle long distance without getting tired. I used the trick of paddling 4-5 strokes on one arm while the other arm rested in front of me and the head resting on the deck, it allowed me to prone paddle 1.3km like a breeze in one go after breaking my paddle after a 5h SUP session at an outer reef...