Hi Graem,
it's a pity you cannot test it. But according to my statistics there's a lot of Mac user visiting my website... As if there's were hoping something new for Mac. I'm sorry for them.
My plugin support only upsizing, so here's your cropped image enlarged three times in attachement. Also, there's parameters you can tweak, and i bet there's settings that could better fit to you taste. Enlarged with default settings.
Mehdi