My 1299SL (4000+ miles) hasn't had a overheat issue - i'm rarely in traffic though, however i do find the temps will creep up quickly even at a red light - the fans kick on at 219F/103.9C...but once moving there is no issue
All things being done: coolant level ok - fans on at 220/103.9C or near there - no leaks - i would ask your dealer if they replaced the coolant....even though it is not called for at the first service i would at least ask - i've had other ducs serviced in the past, and when they replace the coolant, it is very easy to get an air bubble trapped in the system....that would easily cause the temps to rise - it is not easy to determine you have an air bubble short of the temp rise on your bike being stubborn, and seemingly never dropping no matter how much air flow you have going
There is a somewhat precarious way to clear it - the bike has to be leaned way over on its side with the cap off, until the bubble (trapped air) finds its way out thru the top of the radiator....tie straps to the ceiling or your friendly dealer would happily do this for you
Or you could simply have them do a full flush of the coolant, and hopefully they pour it in slow enough to insure a bubble doesn't form....it can be tedious doing a slow pour to refill the system, which is why it is a fairly common occurence