I think it’s a good idea, but in practice it comes across as a bad idea because it never properly becomes part of the story.
I don’t agree with Kasdan’s take on ROTJ but I do think they blinked and if anything could truly be undone I would have wished Gary Kurtz never left, but that’s not really an idea so instead I’ll go with Leia really shouldn’t have been so sidelined in ROTJ.
I think the truth of the matter is having Kurtz around wouldn’t have changed much. Most of the issues present in ROTJ were brought up in the Lucas/Kasdan/Marquand/Kazanjian story meetings. The fact is that Lucas was calling the shots, and Kurtz would have ultimately acquiesced to him, same as the others (the reason TESB is great is because Kurtz basically let Kershner do what he wanted, not because he was keeping Lucas in check).