I'm trying to find out the author and title of a book that was published some time after 2000 , possibly by Baen.
A chemist is on a spaceship whose mission is to observe but not interfere. He is accidentally "killed" in a midair collision with an alien spacecraft. He is given a choice: die, or be relocated to another world occupied by humans living with approximately 19th century technology.
He is modified via nano or biotechnology which enhanced his healing and was transmitted to his intimate partners and children giving them improved wound healing. His knowledge of chemistry and other science topics sparked a industrial revolution in his new home. This attracted the attention of the local ruler whose nation's survival is threatened by the imperial ambitions of one of its neighbors.
The book is not Edmund Cooper's Seahorse in the Sky (1969).
I quite enjoyed the book and hope to read a sequel if it exists.