The "accidental swipe" transaction was the only time we encountered DCC, which was clearly presented on a customer facing terminal giving two prices: ISK 499 or USD 4.80 (made up numbers). None of that red/green, yes/no button stuff.
My mom used her physical card twice at the same store for small NFC purchases. No DCC at all for those or other tapping. I had no DCC on my two chip insertion transactions - ISK defaulted on those.