You're right. To which the teller can reply, "I've crafted an encoding where you are tortured for billions of years." The idea is more about swapping out the s

You're right. To which the teller can reply, "I've crafted an encoding where you are tortured for billions of years." The idea is more about swapping out the substrate of your current subjective experience than creating a new encoding of your current universe. The book has the convient liberty of actually jumping between simulations/encodings to illustrate this, but it's ancillary to the main idea.