Very minor but much appreciated detail would be to provide this like the title states. It's just generally a slightly nicer experience to only have to generate a password once instead of twice or more often to be valid.
Luckily your requirements seem to be very flexible but the maximum password length seems to be 71 even though the error message that appears when you make something longer states the maximum is 72. Either correcting this message or better yet extending the actual maximum would be a nice little improvement.
Otherwise I've found the site's design and flow to be wonderfully made and appreciate the work that's been put into it. Thank your for your time and willingness to view customer feedback.