Good catch!
I already worked on a PR for something I had spotted the other week, so this should be released soon-ish, I guess: 🎨 Improved search keywords in Admin-X Settings by betschki · Pull Request #18608 · TryGhost/Ghost · GitHub
Since I still had everything open in my IDE, I just went through all the settings and added another PR. Now all the fields should be searchable, if this is merged 