The question is how useful this would be in an automatic fashion. The Standard Material is fundamentally different in many ways. Apart from that, if you want to export those you can basically only use a Standard material with only bitmap textures assigned. Every other map and special corona map had to be removed before. While its "possible", the results would be very dependent on your original materials.
I don't really want to include that in the standard Corona Converter, I'd rather suggest doing it externally with a custom script.