Are those all things you've actually done? Or are you making a list of "potential database migration scenarios" like I described above?

As a datapoint, I've been a backend guy for coming up on 25 years now, and not only have I never needed to roll back a database migration, I'm not aware of that ever having needed to be done anywhere, even anecdotally. It just never happens in the reality we live in.

Yet all migration tools support it, require reverse migration scripts, etc. And you listed it in your "must have" list.