That is incorrect, as far as Raphaels Bank is concerned. I have tested it. Yes, they offer “DCC”, but it’s optional. You can declined it, and get Monzo/Mastercard rates. There are plenty of TravelEx cash machines where DCC seems to be mandatory (at least I haven’t managed to withdraw without DCC), but Raphaels Bank certainly allowed me to withdraw some Euros from my Monzo card without DCC a few months back.