The Obi-Wan scene is needless, all he does is tell Luke that Leia is his sister. Cut that. Cut it cut it cut it - do it. Now.
Cut this scene and leave the one where Yoda says “there is another Skywalker.” Trim the scene where Luke and Leia talk on Endor to reflect this
NOW
During the end battle Vader says “you have a twin sister” do a flash of Leia via the Force. Yads did this in one of his edits but if my memory is correct I don’t think he scrubbed all the earlier stuff. Now it was Darth Vader who told Luke that he was his father and now it is Darth Vader telling Luke that he has sister, who is now fair play as a target. The scene makes the Skywalker family tree a revelation to Luke, Vader and the Emperor. Luke losing his cool makes even more sense when you cut it this way. I’ve done an edit of RotJ using the Yads edit as a base (the Boba Fett less one) and it works very, very well.