I read somewhere that the author (the248) will never code uTorrent emulations for mRatio. I guess it's because as uTorrent is so popular, this could rise mRatio popularity too, and he apparently don't want that.
It's also known that you can ask him a custom emulation, given that you provide a sniffing imprint of the client you want. But I don't know if you will get a custom uTorrent emulation this way.