AMEX Credit card from Swisscard with 1% cashback

Do we have some recent experiences with Booking.com and Amex? I used my Amex last time in October to book a flight via Booking.com. Paid in CHF and no extra charges. Now it would be nice to save a few francs on my upcoming stays, but I do not want to risk it if they apply ‘foreign’ fees for CHF transactions abroad. Thanks in advance!