I can always override an individual pull invocation with either "git pull --rebase" or "git pull --no-ff", making it a conscious choice when a fast-forward pull is not possible.
Oh wow, this must be a recent feature, I remember looking for a way to configure `--ff-only` by default a few years ago and it didn't seem possible. I ended up making a git alias of `git puff` which calls pull with the `--ff-only` flag.
