You can enable the auto correct feature setting the AutoCorrect property of the UltimateSpell child control to True.
It will correct a misspelled word automatically if there is only one suggestion. Otherwise, it will leave the word as
underlined to be fixed by the user manually. This is how it works in Microsoft Word.

In this text, "cleanlyness" has only one suggestion. If you go to the end of "cleanlyness" (right before comma) and
press space it will automatically correct that word. You can experiement with your own text as well.