There you go, thinking like the engineers… They thought of that, too, don’t worry: “rear swing arm is protected from paint in the contact areas between swingarm, final drive and mounting nuts. In order to protect these areas from corrosion, swing arm has ‘NANO PROTECH long term corrosion protection’ applied.”
I’ve yet to notice any rust back there, so I guess the stuff works.
“Protected from paint” would read “masked off during painting” in American English. And notably, I don’t believe they mask the FD case in the contact area. So the amount of squishy paint/coating was reduced, but not completely eliminated. Perhaps the key was eliminating the paint where the washers bear against the swingarm. I keep checking the Nord-lock ones anyway, but I’ve seen 950 miles on one with no loosening of the nuts.