While Ron and Hermione are there for all the heavy action in the film, they don't quite get the same character growth and attention that we've seen in other films.
But hey: what are you going to do? It's an action-heavy finale to an adventure series, so we can't really expect a lot of cerebral dives into the changing motivations and feelings of every character.
One nice thing we should note: Ron continues to step up and impress everyone with his smarts and helpfulness in the effort to defeat Voldemort. For example, Ron is the one who figures out how to destroy the Horcruxes without the Sword of Gryffindor—which is a huge deal:
RON: Harry, Hermione and I have been thinking, it doesn't matter if we find a Horcrux.
HARRY: What do you mean?
HERMIONE: Unless we can destroy it.
RON: So, we were thinking—
HERMIONE: Well, Ron was thinking. It was Ron's idea. It's completely brilliant.
RON: You destroyed Tom Riddle's diary with a basilisk fang, right? Well, me and Hermione think we know where we might find one.
So, yeah, it's all well and good that Harry's figuring out where these Horcruxes are, but WTG Ron for figuring out how to destroy them. That's a key discovery, and it shows just how much Ron has grown up…and what an invaluable member of the group he is.