Plus, her doing such a thing would require “all the strength she has left”, meaning she’d be dead before Endor. The reason it has to be Luke is that he isn’t confined to the rules of Force projection anymore since he’s a ghost.
Hard disagree. You could always change the context of Leia’s death to be healing Ben of his wound or summoning the spirit of Han. Leia spending her lifeforce to just distract her son by saying hi has always been a disservice to her character.
JEDIT: Using the Leia dialogue from the DotF script better serves & sums up her character as a whole. I admit, doing so they way I suggested robs an easier location to place a spot for Luke to speak to Kylo. My best solution for that would be take the first time Kylo talks to Vader’s helm in TFA, reverse it, and add the cracks in his mask in with photoshop…actually, having Luke speak first would actually play better into the Leia/Kylo dialogue I currently have, since it better sets up why Kylo would even mention Luke to his mom.