I think the bikes that have shown signs of melting master cylinder are the bikes that set in very slow traffic in very hot areas of the country.
The MC cap melts at highway speeds, not slow speeds.
One good long ride on the Interstate when it's 90F+ out will melt it thru. The temps under plastic reach insane levels (300F+) at highway cruise rpms. 1 up, no traffic. I suspect people that haven't had it melt yet don't ever do 400+ miles in a day which could explain the "mine didn't melt" comments. Not everyone travels on their Spyder.
On a positive note, I was able to cook 2 potatoes and broil a package of hotdogs by wrapping them in foil and placing them under the seat. Just make sure you turn them over when you stop for gas. This never worked on my '09 no matter how many times I tried.
Remember that other things are melting too, parking brake lines are melting, purge valves are failing due to heat and evap cannisters melting thru and bursting into flames.
The recall will bandaid the MC melting issue and possibly some of these other melting issues. But it doesn't solve the heat issue.
In order to have a safe and sane 2013 ST you will likely need the new side panels (which aren't available to buy yet) which should dump enough fresh air into there to completely mitigate the heat while in motion. These parts are probably $400 plus paint (the 2014 colors don't match our 2013's.)
Unfortunately BRP lawyered up and labeled these as a "appearance enhancement" rather than cooling ducts which they obviously are. They won't and can not admit to a flaw or there will be hundreds of lawsuits no matter what they do to resolve the issue. They could be giving away free bikes and if they admit it's because of a high heat issue then someone will sue them for melted... dangly bits. "Ow I spilled my coffee, I want a million dollars."
Maybe they will offer a discount on the new parts for 2013 owners, that'd be nice.