Progress update: I just updated my repository, and I'm fairly sure that I've inserted everything I have in the script, with the exception of a couple of post-game things. So in theory, 100% story. But I could be wrong.
(I'm guessing the unofficial patch below uses my repository as it was a couple hours ago, which was up to the Ancient Castle. So that's still most of it, and the Elite Four onward has been there for a while.)
Of course, there are still plenty of untranslated trainers and other NPCs on the way. (The massive file with all trainer dialogue should have all the plot-required ones, but is around 20% done overall.) From now on, I'll probably be testing linearly, making sure things fit in the boxes and that pretty much EVERYTHING I can find is translated. (Before I went all out to insert the plot today, that process was complete up to Sky Arrow Bridge, though there was a designer's house in Shippo which I couldn't find the file for.)