Totally agree, Kay. I know the piece, A., and if you learn this slowly and thoroughly you’ll find it used again and again, and in the next variation it will seem less tough, and twenty pieces from now you’ll wonder why it seemed tough in the first place.
As you said, it definitely is an essential technique, but no particular short cuts. That said, if you happen to know a little chord theory it helps a little to analyze the chords. If you go through the piece you will find repetitions, and finding that you are really only playing the same few patterns makes the task a little less daunting.