[Jellby]

I use a plugboard to send to the Kobo the author_sort that I have in calibre, but replacing spaces with non-breaking spaces. That way I force the Kobo to sort exactly what is shown.

By the way, Spanish surnames are a source of headaches, "Gabriel García Márquez" should be sorted by G, "Miguel de Cervantes" by C, "Vicente Blasco Ibáñez" by B, "Lope de Vega" by V, "(Pedro) Calderón de la Barca" by C, "Jorge Luis Borges" by B... you have to know which is given name and which is family name, automatic methods are bound to fail.