In the digital age of Kindle and POD is a book ever finished?
About five years ago I self-published a novella "The Spoils of War". In the middle there's a section where the MC is packed of to Pakistan because the family don't want to face the embarrassment of her actions in the UK. The story focussed on other characters until the MC returns.
After publishing I spent a year - troubled. What the character did in Pakistan added very little in to the story but, regardless, it bugged me.
18 months after publication I added two chapters of her experiences in Lahore.
Another three years passed. In the original ending, whilst you (the reader) was wondering if she'd ever forgive the boy . . . she ran off with the girl! Maybe smarter readers could have seen that coming in the subtext but I felt mainstream readers may be put off by an extended focus on 'gay sex'.
The world changed very rapidly. I felt the need to add two new scenes. Two previously straight girls (one of which who is pregnant) reach the logical conclusion - they should be together. However, I thought it would interesting to detail the girl's trial runs before committing to a life without the 'dumb stick' and how their first attempted at intimacy required several bottles of Vodka.