On my last trip through ICN (late 2019) I had a 1 hr 10 min connection coming from BKK and it was tight. By the time I cleared transit security in ICN and made it to my DL gate, boarding was just starting. That being said, I remember on the outbound seeing several KE agents greeting the flight with signs clearly showing passenger names that had very tight connections and they appeared to be escorting/fast tracking them to get them to where they needed to go.

So, I would definitely prepare for the chance of a misconnect (and also what that means in terms of Covid regulations) but also know that if there is any chance of making the flight, the agents in ICN will most likely try and get you to the flight.

As for seats, I was in 2J on the 339neo last month coming back from AMS. I appreciated being close to the front for meal and beverage selection, however found the noise from the galley to be a bit loud. I do prefer the "J" side on the 339neo because you can either walk to the rear lav located on that side, or go up to the front lav. If on the "A" side, you have to go up to the front lav and then walk back down the J side to get to the lav from what I could tell (didn't see any easy way to get to the rear lav from the A side unless the curtains were obscuring a path). Even-numbered seats on the window sides have the seat closer to the window.