It shouldnt be nessesary imo if its something like "threee" since its stil readable, and the question is old
Id understand if you were changing "Ihav aa pokrmonb and i domt kbow how tob red for eggg moves" to "I have a Pokémon and I don't know how to breed for egg moves", since thats a lot of mistakes, and the silent edit feature would be useful since no one really needs to know if you fixed up some grammar or spelling.
But theres a good chance an expert/editor/mod will have gotten to that already.