My current working hypothesis is that the Indians successfully secured independence from the British Empire some time in the mid-19th century, then formed a subcontinent-wide government to prevent any of that sort of nonsense from happening again, sidelining the Mughal Emperor in the process because he was
clearly about as useful as a screen door on a submarine.
Since India at the time was a bit...
loosely connected... the resulting government called itself a 'confederation' and includes a number of nominally semi-independent 'princely states' and whatnot.
But I have no special information from the author here.
Also the idea of Australians not colonizing the most dangerous planets in the Concert and becoming Napoleonic-Catachans feels like a lost opportunity. And is Space Mexico a thing, or are they still part of Space-Spain? Are they constantly in a race with America to grab more worlds, as a galactic "Fuck You" for the land they lost in the Mexican American war?
Mexico's declaration of independence from Spain predates the point of departure, or at least stands well outside its "light cone" in terms of happening too soon for the first machines to realistically butterfly.
By contrast, the Mexican-American War takes place in the 1840s, by which point the existence of machines is
very likely to impact the chances of the United States going to war with Mexico.
And the question I think we ALL want the answer to: Did Texas become its own Space Empire?
The historic processes that for Texas would be kind of short-circuited here. Machines are invented in the early 1820s, right around the time that Anglos start filtering into Texas to settle (often dragging chains of slaves along with them). By the 1830s, machines have
probably at least started to spread to Mexico and are also disrupting the plantation model of agriculture in the American South, though it's unclear just how machines interact with American slavery or how that plays out in the timeline.
Basically, nearly every relevant economic process and political process that drove first Texas' declaration of independence, then its ability to enforce that independence against Santa Anna, then its power to hold out for a decade or so, then its unification with the US, would all be getting heavily butterflied. The butterflies might form any number of complicated and exciting interference patterns with any of a number of outcomes.