I have to admit I agree with Testing here. The reason Palp’s goes with clones is because their free will can easily be manipulated. He might even be able to will his spirit into them without any killing involved since they’re just a copy of his body. Also, I’m not even sure that there were many powerful Force users left in the galaxy. He resorted to clones as a failsafe in case he dies somehow when Luke denies his request.
I feel as though I disagree with this one. Judging by inferences from the actual movie, Sith essence transfer only works if another Force-sensitive kills him (whereas Darth Vader threw him into the shaft, Rey reflected his lightning at his face - he essentially committed suicide).