Nothing really super unique or wild.

You will have Korean Air lounge access at HKG which is just standard older place. At ICN, the entire terminal where KE operates is brand new just three months old with a lounge only for first class passengers. No fast track at ICN.

I believe the offer special luggage tags with your name made while you are in the lounge.

On the flight from ICN, be sure to eat the Korean meal as KE shows off the special farm in Jeju where they raise the cows and animals and grow the veggies for first class food.

On your HKG ICN flight, if the first class cabin is sold as first, it will be first service....which isn’t tooooo different on a short regional flight.