The change in Darem was the whole point of the Calica/prank episode. He went from needing to be the best (because of his parent issues) to apologizing to Genesis, supporting her as their team leader (with the prank as well), and telling his parents he's found another way.
With the Miyazaki episode, he immediately gave Genesis credit for the idea of how to find the cloaked ship, and while he didn't have lines for it, when she was getting frustrated with the search, his body language and gestures were essentially encouraging her.
Personally, I hope Jay-Den and Darem become/stay close friends. I think boys and men need more close, intimate, platonic friendships as a whole.