Changing currency at checkout

It doesn’t seem possible to update currency at the checkout step. Is that correct?

Sometimes customers realize they are about to check out in the wrong currency when they’re at the checkout step. It would be nice to allow them to change their currency at this point, in the checkout, instead of forcing them back to the store to change it.

Is there any way to do this now, or is there a discussion of whether this will be added in the future?