Looked after and with some specific preventive measures there's plenty that reach decent mileage.
Cam followers are/were a known weak spot and recognising that early can prevent damage to the cam etc.
Not every one has problems with fuel pumps but many do.
KTM light gauge wiring can be suspect if it's been rubbing.
You're right in them being a duel purpose engine with longer service intervals than many of the exc range.
So apart from the cam follower problem, mechanically it's a strong LC4 engine that should reach a high mileage ie. 80k plus, cylinders are Nikasil plated and very long lasting compared to much fabled Honda XRs etc etc ...... but then there's the electrics and fuelling systems, oh and suspension