Cashback retailers

Just wondering, if I would upgrade to curve black, (now on curveX) then it’s possible to choose 3 cashback retailers, but is it possible to change those in the app and how long is your choice frozen?

Keep in mind that once you confirm your choice of retailers, you won’t be able to change them.

Ok thanks, too bad you can’t change them. Because some of the listed retailers don’t allow to even pay with the curve / marstercard or visa.