Hal, have you considered having Luke speak to Ben during the Mustafar Opening or when he is repairing his mask? Maybe just a quick line like “Ben”, but something just to be consistent with Luke’s last words in TLJ of “see you around kid”.
Remember Rise of Skywalker is the true sequel of The Force Awakens, so it doesn’t really care either happened in the last movie. 😉
🤦♂