5 with reasonable acceptance and use, even advocacy, for up to 1. I don’t see a difference between 4 and 5, though.

Reviews should be the norm. Even for simple changes, a simple code change should be simple to review and approve, too. At the same time, some formatting changes or small or minimal changes with high confidence can be pushed to main without review - that’d be just wasted time and effort on the reviewer’s side. High urgency can also warrant an immediate push to main, or live hotfixing on prod if possible, with a corresponding PR still open.