My 75l frank custom weighs 4.2kg
What dims is yours? Are you winging and parawinging it? Im doing 6', 20", 73L (80kg).
5 11 by 19.25. I'm same weight as you. My only board for a long time has been a 60l kt custom which is very similar to the current super k v2. I've started dabbling with parawinging and wanted more volume to make things easier.