I read them as a kid, but didn't catch on to the undertone of stress. At least Baum eventually got the hang of writing about new characters in new countries, having them show up in Oz in the last couple of chapters, and calling it part of the franchise.

And I can't be too sorry about the pressure on him, because Patchwork Girl is one of my absolute favorites, and that's the first one he wrote after killing off Sherlock Holmes for real announcing he was definitely done with Oz forever...