Sorry to overload on questions!
Just a quick comment on chains and so called "miracle" sprockets. What some riders miss ... especially those who ride mostly off road ... is that a sprocket can be TOO HARD. I've read several forums were dirt riders declare that their Ironman sprockets went through two DID VM-2 X-Ring chains and their sprockets still look new. They were thrilled!
See anything funny about this?
I get 25,000 miles on a DID X-Ring chain. Think those guys went that far ... on their "dirt bikes"? I doubt it. Most dirt riders do a couple thousand a year at most.
I've used DID chains over 250,000 miles, going back to 1997.
I normally run OEM sprockets when available or JT, AFAM or Renthal when OEM not available. No idea if KTM supplied sprockets are good ... or not, but they would be my 1st choice for RTW. Buy two!
Lots of "Snake Oil" miracle sprocket/chain hucksters have come and gone, like Larry "Vic" Krause and his Sidewinder products of ill repute, who has been around since the 70's.
I've not used Ironman but I do know a bit about metallurgy. A case hardened sprocket is of no advantage for overall chain life. Sure, it never wear out ... but how is your chain doing?
A new chain can cost around $120 to $170 to replace. More in some far away place. They are heavy and hard to pack. On long rides on my DR650 I always carry a spare front $15 sprocket (JT). I change it out every 10K miles no matter what. I've found that a fresh front sprocket adds LOTS OF LIFE to my chain. A front Sprocket is relatively cheap and easy to replace. Chains, not so much.
A super hard sprocket may look NEW ... but can wear your nice new chain in short order. You may only get 10K to 12k miles before chain shows signs of failure. My current DR650 uses a 525 chain (your KTM uses 520). My original chain went 12K miles (medium quality DID). Replacement DID VM-2 X ring went 24K miles. Current DID is now up to 12K miles ... has never needed adjustment, looks NEW. I just changed to a new front sprocket: OEM Suzuki. 45,000 miles on bike ... and counting.
Japanese engineers claim sprockets "should" wear, rather than the chain wearing first. In any case, keep chain clean as you can, light oiling, no sticky stuff.
Good luck! Looking forward to more reports.