The schwa has many spellings. The /ɔɪ/ diphthong is spelled <oy>.
The dictionary only yielded four pairs including one weak form. Clearly this distinction does not constitute a problem for any leaner.
The density figure is 0.5%. There are 3 semantic contrasts, a loading of 75%, though this is hardly significant.
Allah alloy tanner tannoy tanners tannoys to toy
Credit: John Higgins