I never saw the Chassam Sofer inside but I once heard a shiur about metzitzah bapeh and this Chassam Sofer was brought down. The way it was explained is that when the Chassam Sofer heard that it might be a sakanah, he said that metzitzah bapeh shouldn’t (or doesn’t have to- I forget which) be done because it was only instituted to protect against sakanah and was never an ikar part of the bris. But when he heard that the person who asked the question was actually a reform Jew who just wanted an opening to mock, denigrate, and eliminate this tradition which to him seemed archaic and backwards, he was chozer and said it must be done (I assume he meant unless you know for sure it’s a sakanah).
