One challenging feature of Dark Light, at least so far, is the introduction of new "civilisational worldviews." More than the POVs of individual characters, we now begin to see through the mix of peoples in the city (country?) of Rawliston on the continent of New Virginia on the planet of Croatan (p. 15).
Chapter 1 gave us a Stone Age civilisation with the capacity to fly by glider, with a focus on Stone, whose most interesting feature is he/him pronouns but identifies and, most interestingly, is identified by other characters, as a woman. And speaking of identity, what's complex is how these...communities (?) refer to themselves.
Those who call themselves "flying people" refer to "savages" that they simply call people, but they also refer to Christians, and I'm not sure the Christians are savages here. Maybe? And it might be related to the smuggler economies mentioned that allow the flying people access to the forbidden like steel tools such as needles, scissors, blades, etc.
In Chapter 2, we get references familiar from Cosmonaut Keep (saurs and krakens) but also "heathens," who I think are what the Chapter 2 civilisation calls the Stone Age "flying people." The Chapter 2 characters we meet (Gail Frethorne, mechanic) seem to have 20th century technologies like radios, cars, telephones, and planes, as well as a few bits of minor alien tech from the saurs. They don't seem to act like Christians (other than calling non-Christians heathens).
Maybe for now, it's just about stoneworkers who fly versus metalworkers with cars. There's a clear division between them, although I think they work together (not sure if I get this right, but I think the cars pull the gliders on the ground until the get enough lift). This preoccupation with flight might be because of the arrival of the Bright Star two hundred years ago, which brings me to my last point...
...we get a timeline, from Lydia's perspective.
SOME SPOILERS HERE
Cosmonaut Keep was half-set in the planet Mingulay, a "daughter colony" to Croatan, where Dark Light opens. I'm trying to get a sense of the history. Croatan is seven centuries old. 200 years prior, when it had been around for 500 years, the Bright Star arrives (from 2049) to Mingulay. Eight years after (in 2057), information (and) technology from 2049 Earth from Mingulay ("shipments of downloads" says p. 33), reaches Croatan, affecting their industry and introducing a fixation with flight capability. The distance between the two colonies is five light-years, so the Bright Star took three years before it started sending and trading with Croatan. 2049 and 2057 are Matt's earth time though; in the Croatan calendar, it's around 2270-something, so 221 years in the..."future" but not really. This means that the "latest" peoples of Croatan who were already there were from...200 years prior, so already industrial (1828 to 1849), making the daughter colony 200 years advanced given what was already available in 2049 and consequentially, Croatan, became 200 years backwards. Of course, we also don't know how many Earth humans have been sent to Croatan: 700 years is 1349, medieval feudal, 500 years is 1549 (the Croatoan disappearance was discovered in 1590). Another planet we haven't been too yet is where the de Tenebres live: Nova Terra, whose main city Nova Babylonia just celebrated its tenth millennium. I'm not sure how that works. They're an alternate human civilisation in the year 10000? When were they founded? Or were they perhaps not founded by humans but by saurs and/or krakens, with humans like the de Tenebres only brought later?