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. Other have complained about “the lateral clearance clank noise”.
Outback motortech is also doing a centerstand. €165
For those of you who don’t like a center stand, some useful gadgets exists to replace it, either out there on the trail or in the garage. One that works is the EnduroStar TS3 Trail Stand, a very compact tool that can squeeze anywhere. $40. BDCW even drilled holes in their skid plate to accommodate it.