If you change to swept fins, your performance and ability to foil will be so bad, that nobody seem to do this on full raceboards (I've talked to some of the best kite racers here who confirms this).
So when you got loads of sea weed for an event - how do you cope with that ?
Just let the kite plow through ?
Jumping and trying to get rid of it in the air ?
Dropping backwards in the water and just wait ?
Dropping backwards in the water and turn the board or clear the fins with your hand ?
PS: On freerace boards it is very different, and anti sea weed fins are used - but that is not the question here....