Getting back onto the same train won’t be possible if I have to touch out and in.
Is there really no way to obtain the much cheaper TfL fare in the southbound direction, or in the northbound direction if the first northbound arriving train is a Southern train, without waiting for the next train?
Also, does it take much longer if I travel through Whitechapel instead of London Bridge coming from Farringdon, or change at Canada Water going back to West Hampstead? By touching the pink reader at these stations the fare will become on the TfL scale.