> You mention that trait curiosity doesn't give you anything, but does state curiosity?
I shouldn't say that trait curiosity doesn't get you anything. It may correlate with some benefits, though it is not clear to me that trait curiosity research has sufficiently proven that trait curiosity gets you more than higher intelligence does. From my reading, pretty much all of the benefits claimed by trait curiosity are just the benefits of being smarter, so I'm not really convinced there is anything there.
With that said: yes, I would say that in my research and my general sense, there is a noticeable effect size between state curiosity and performance. This includes being objectively correct in problem solving, ability to recall over time (better memory), better memory accuracy, etc.
> Could choosing to work in a field that one considers more interesting lead to more state curiosity when doing that work?
I think this is probably true. Certainly there are proposed links between interest and curiosity in the literature. Some, I would say, argue there is no difference, though I think there probably still is some difference. I am interested in certain type of art, for example, while at the same time not being curious about how it's made or anything else about it apart from wanting to look at it.
Believing what I believe, if I wanted to perform better and be more stimulated by my work, I would certainly focus on interest and curiosity. But I am biased, because I work on curiosity itself. I am literally curious about the thing that makes me curious about itself. :)
If your goal is fame or money or power, then following your interests and curiosity might not get you there, of course.
Could choosing to work in a field that one considers more interesting lead to more state curiosity when doing that work?