Center stand for the S (P/N 63503916044C1, £175) and for the R (P/N 63503916144C1, £175) have been announced at your nearest KTM dealer. Availability is announced for August.
SW Motech has one for the S (manual), and one for the R (manual). Both at the price of €180. Example of install. Some complaints of the arm being a bit too short, with insufficient leverage making the operation of getting the bike on the center stand hard. To the point of returning it.