Re: the topic of premiseless gaming, I think some people like having a tuned sandbox (which this is an example of, or something like Ars Magica: highly flavorful but without a lot of “and now you do this”; you’re expected to come up with that on your own) and some like it more generic (see HERO and GURPS) and some have a lot of baked in plot (games with a lot of meta and faction like Vampire). I tend to think of modules as a way to add premise and impetus to the first kind, seed stories for GMs who don’t want to build it out of whole cloth. I feel like HERO and GURPS tended to release source books to reflect how people who use universal systems are looking more for toolkits to add to their stories, rather than the story itself. Splatbooks for Vampire etc. usually enhance the story as well as add history and mechanics to the game.

Though there are definitely fusions of this…. For instance the Spinward Marches source material in Traveller, which let campaigns hook onto an overarching metaplot (which had the lovely structure of advancing in time) even though you can play it as more of a sandbox game if you just use the base game.

So maybe the “What do you do” is up to the group in the base material, with supplements for maps for those groups who don’t want to whole cloth it. (There are definitely some brilliant modules out there, so it’d be a fine tradition to follow.) Since this is a newer game, there might simply not be as much supplement support yet, or perhaps its core audience doesn’t mind constructing the premise. I definitely know GMs who wouldn’t touch Ars with a ten foot pole (“too fiddly, too much work”) and some who took to it like a duck too water.