If you have to have em as midi, run more than one Superior and set em to Cached mode and clear the memory. It'll use like 10 mb tops for a cymbal.
But yeah, if I ever really need to split the OH's I'd just bounce em out as wavs thru Superior and go from there.
Edit: Just to be clear, it'll bounce the whole drum track like. So you'll have whole cymbal tracks as audio.