I’ve said this before but a simple dialogue tweak would fix this. If Luke had said to Leia “I have to turn myself in, I’m endangering the mission. The Sith can feel my presence and know that we’re here. I’ll allow myself to be captured - Vader will take me to the Emperor himself and I will make sure he’s on the Death Star when the attack is launched”.
That would just make Luke a “captain obvious” to those in the audience who cannot make 1+1=2 on their own. On the other hand, it would ruin things in-universe. Luke probably knew and accepted that it was a suicide mission and that he would most likely die if the Death Star was blown off (whether or not Vader was redeemed). Why the hell would he tell such a thing to Leia and make her upset before such a crucial mission she was about to undertake? The way he handled it was very wise; he did not lie but he did not tell her that he is going off on a suicide mission either.