Win7 + H.264 Encoder + IMFSinkWriter Can't use Quality VBR encoding?

I'm trying to alter the encoder quality property eAVEncCommonRateControlMode_Quality via ICodecAPI.

However the setting is ignored as started in the documentation which says the property must be set before IMFTransform::SetOutputType is called.

Now here is the problem: the sink writer seems to call IMFTransform::SetOutputType when we call SetInputMediaType on the sink writer, however if we don't call SetInputMediaType we can't retrieve the ICodecAPI interface via sinkWriter.GetServiceForStream (throws exception) to change the quality setting..seems like a catch 22. I'm hoping it's me and not just a design flaw in the APIs.

Setting the quality property works on Win8, as Win8 does not ignore if when called after IMFTransform::SetOutputType is called.

Help!!