Consistency

I think you're right: the record is there to be worked with. I can make some minor changes in HP and I can think of some interesting twists for the next novel that would allow for Grimly to enter Krothen's court but for the struggle over succession still to be going on. I wish I could spell out more, but it depends on a character whom you haven't yet met, who only shows up by reference in HP.

Throughout, I've tried hard to be consistent, and haven't always succeeded. That's a problem with an on-going story, especially one written over so many years. If I'd waited to know everything, I wouldn't yet have started. It's been a big help to have such knowledgeable readers. Apparently George RR Martin similarly depends on a couple in Sweden who have an encyclopedic knowledge of his work. Bujold is right too that stories grow in the telling, but I'd rather think of plot loopholes than contradict myself. It's spotting problems in time that's the trick.