On two-stage exams: I typically have students in my introductory physics classes discuss their exams in groups on the day following the exam. It's not graded, though. Despite that, I still see some of the most intense participation of the semester. I do tell them that any reflective comments they add to their exam could potentially give me context while I am grading later on. I welcome their thoughts into the feedback-conversation.
On two-stage exams: I typically have students in my introductory physics classes discuss their exams in groups on the day following the exam. It's not graded, though. Despite that, I still see some of the most intense participation of the semester. I do tell them that any reflective comments they add to their exam could potentially give me context while I am grading later on. I welcome their thoughts into the feedback-conversation.