The only thing I might consider adding, is making it clear he had other experiments (implicitly including the Palpatine clone he now inhabits), but that Rey or Kylo still would be better vessels. I’d also include an angle about Palpatine wanting to kill her if he couldn’t possess her - but I think this core principle is the right angle.
I’d love to include that as the first sentence of the final paragraph, but we’d miss out on “as a Palpatine” which is essential for the rest of the movie’s dialogue to make sense.