Indeed, I understand that they are not major characters in the game, but still I would like to see a bit more.While I agree with you and I would have loved to have seen more of those characters. They were never going to play a major role in the game, they were only side characters. We will hopefully see plenty more of them in their next game Firebreak, where Tara as far as I'm aware becomes one of the main love interests.
Let me say that, for me, one of the best scenes in the game (and in many games) was not with the major characters, but was in that night in the hut with Rikki and her mother. A five star scene.