Correct way of managing calls to MFXVideoENCODE_EncodeFrameAsync()

Hi

When I call MFXVideoENCODE_EncodeFrameAsync(), what is the recommended way of managing the syncpoint(s) and bitstream(s) variables that you pass into this function? I'm wondering because I've seen different ways how people implement this. One way I've seen is to reuse one bitstream and reuse the syncpoint for every call you make to MFXVideoENCODE_EncodeFrameAsync().  The second solution I've seen is to manage a pool of bitstreams and syncpoints. 

I've heard that the second solution is the preferred way; though it seems like a design flaw to create multiple bitstream objects as one bitstream should be enough to handle the output of the encoder.

Anyone who can share some advise? 

Thanks