Boo, I was afraid you'd say that, but not surprised. Yes I'm pretty sure it hasn't written the changes, at least, I can't see them when I view the metadata in my library list, and in the meantime, I found this thread:
https://www.mobileread.com/forums/sho...etadata+review
Suggests that it will take a while for it actually write my changes when it gets to it. I'm glad I started this by Author and didn't just leap into the whole library!