I wait until 9am because I don't want to be part of a normative pressure to work all the time, especially when there are devs on the team who are junior to me and therefore might be more easily pressured.
I don't really work outside office hours much, but as a personal policy, when I do I don't commit or push (which triggers CI builds).
I don't want to build any expectation that I work outside the office, because I generally don't. I have my own things going on, and literally anything else takes priority over work outside work hours.
