> Does his character improve throughout?

Hell yeah he does, I didn't like him in the beginning either. But by the end, he was my favourite.

The first season of The Expanse is difficult for many people and even though I only needed a couple episode, I can understand why.
As someone else already said, seasons 2 & 3 are absolutely phenomenal though. Some of the best TV I've ever seen.

Season 4 is not bad either, but not as great as the previous two. Seasons 5/6 are still good compared to other shows, but overall a bit disappointing I would say.