I only learned that checkbox "This is a minor edit" has the access key while looking at html itself.
- Add access key explanations like this: "This is a minor edit (Alt-i)"
- Add the checkbox in "Personal Preferences": "Disable access key explanations" -- for those who doesn't want to see them
This is in addition to the existing "Disable access keys" checkbox.
If implemented, more users will learn about this convenient feature.