It would probably/possibly work without them but the issue with folding kayaks on the sea or rivers is more impacts, there’s a lot of rocks in the fun rivers and in the ocean/sea there’s reefs and other abrasives.
Whereas with a rotomolded kayak its durable enough to even be used for rentals in those conditions. You pretty much don’t have to give a shit with a rotomold since they can take a lot of abuse.
Also keeping the evaporator from getting covered in ice where it doesn’t work. Yeah you can defrost but in certain weather it’s just going to ice up immediately.