Absolutely crazy. Membrane sails are the future, and some lucky folks have them now. I picked up a used 2015 5.2m S-1 Pro I found online for a third new. 2.45 kg!! That is 1.2 pounds lighter than my smallest sail, a ‘09 4.3m2 S-1, and over 2.5 pounds lighter than my largest, a 2015 6.3m2 Freek. It is obvious just holding the sail in its sail bag. The total rig is under 16.5 pounds!
I wish I could weigh my old DeVries 5.5m2 RAF wave rig from the 80′s to compare. We have come a LONG way folks!