To my experience SK is one of the very few airlines which regularly pays out compensation for flight delays without much problems. Claimed doZens of times for delays with SK flights and always got the money, no questions asked.

8 weeks waiting time is kind of normal, they seems to have quite a backlog there. But as long as you got a message that the claim was received they will get back to you in time.

Only Elites (Gold and Diamond FFP members) get a bit more attention, for Diamonds usually in a few days.