Just got back from about 50 days in Europe this summer. In Ireland, ran into DCC at most tourist shops (Woolen Mills, etc) but always offered the clear choice to pick local currency. Same at the Royal Delft factory in the Netherlands for a large purchase as well as Fragonard in France. Only place I have experienced "sneaky" DCC was with Europcar in Scotland. Disputed that with the manager via email and got a credit without having to dispute it.
I used Apple Pay for most of my charges and the only CC problems I ran into was trying to pay a 50EUR parking fee in Brugge Belgium and buy gas in the Netherlands at automated stations that I could not because none of my cards (CSR, Cap1 GM Card) offered chip and pin.
As I understand it, unattended gas stations in Europe sometimes don't accept cards from other European countries as well? Surprised the parking fee didn't go through without a signature as Approved though.
I don't recall DCC in Ireland two years ago using my phone almost exclusively.