‘Billie Lourd played Leia Organa and other visual effects secrets from 'Star Wars: The Rise of Skywalker’:-
^ with ILM Visual Effects Supervisor Patrick Tubach - an interesting article, and covers why there is no Ben Solo ‘Force Ghost’, The Ghost ship (& others), and ‘what you see is what you get’ with Palpatine…
‘Star Wars Took A Different Approach To Maz Kanata For Rise Of Skywalker, But Worked Hard To Make It Seamless’:-