As I understand it inductions generally take longer than a spontaneous labour. With an induction you're "forcing" (for want of a better word) your body to have the baby before it is fully ready - so you're starting literally from scratch. With a spontaneous labour your body has had time to prepare - your cervix is softened and somewhat dilated and the process is generally shorter. Perhaps you were almost ready to start on your own with Kynan anyway...I had an induction with my daughter and it took 18 hours
Not sure about the BP question - a number of factors would come into play there I think.