I personally don't have any trouble with that. Using Sonnet 3.7 in Claude Code, I just ask it to spelunk the git history for a certain segment of the code if I think it will be meaningful for its task.
4.5 Sonnet, but because I've been stuck on 3.7 Sonnet for so long due to corporate policy I wrote the wrong thing.
And yeah corporate policy. Opus is not available. I prefer Codex for my personal coding but I have not needed to look in the Git history here yet.