I'm not surprised that you can make a jump from 1k to 12k because you are honing with the 12k at such a higher angle. When you add 2 layers of tape you only touch the VERY edge of the bevel to the 12k, so you are making an extremely narrow double bevel, so it wouldn't be hard to remove metal quickly at such an extreme angle. At least that's why it makes sense in my head.