I spend most of my riding on my KTM, the VFR sits alot but ridden ever 2 weeks to a month, but it has 115,000 miles on it, all on mostly cheap oil, never has showed slippage (DIESILS OR CHEAP MC OIL).
My ktm on the otherhand, never had slippage either, till I began running a full syn oil, including a new oem clutch pack during that time, EVEN ADDED HEAVIER SPRINGS(still had issues), I scrubbed the plates and went back to Dino oil , no more issue.
Both plate sets were oem. but first plates set 50,000 mile no issue, 2nd plate set 15,000 miles Dino oil , but plaqued with full syn oil , high load slippage. Both oils the same brand, and both rated MA2, but the dino oil is best for the clutch.