I loved The Calculating Stars and have at least the second one on my kindle to read at some point. Though I think I did see some comments about some plot elements in The Relentless Moon that might be uncomfortably close to current events (but by the time I get there with any luck the events will no longer be current).

The only KJ Charles I've read so far is Proper English, which I really liked, but I do have several other in the kindle TBR too!