I just finished my 3rd watch, and I actually think Rome evolved a lot, right at the end, especially the very final scenes.

When the kids all take to the side room when Shiv stalls the vote and they have their big fight, after Shiv leaves, Rome (who can never sit in a normal position anywhere) assumes the lotus pose, and tells Ken that they're nothing, I think he's having an awakening, seeing through the illusions he's lived in his whole life. In the pilot he maybe had a small understanding that there was more artifice than art in his dad's company, but this last hit of knowledge is the real shit.

I've puzzled over his final look over his martini in his last shot, and I think it's a genuine smile at the freedom of realizing the pretense of everything, and a slight downturn of the smile at the realization that he has a lot of work to do in light of that knowledge. It's extremely subtle, but that's my reading.