Hi there aknavay, Thank you for posting the thread regarding the frame flex issue. I have a 2013 CC RSLA which is identical to yours but 3 feet shorter.
I have been resealing both sides front the front of the nose back to the curve intermittently for a couple of years now. I am the original owner and this started maybe half way through our last 6 years since it was new Nov 10 2012. The only thing I can think is we took it on a particularly twisty and bumpy road a few years ago and maybe my TrailAir pin was not inflated enough. The flex only shows while hitched and varies from just the Proflex caulking looking squished (like it was stretched and then re-compressed) to an 1/8"-0" tapered amount of flex(open caulk) on the driver side closest to the front. I have resigned to re=sealing every trip or two.