NVENC SDK (2.0 Beta) question: IObuffer allocation, is more buffers better?

NVIDIA_Video_Encoding_Interface_PG_V.2.0.pdf -

"2.7 Creating Resources Required to Hold Input/Output Data
...The client should allocate at least [4 + No. of B-Frames] Input/Output buffers."

Does allocating more than the minimum required# IO buffers improve encoding quality in any way? Specifically, if I’m using the “2-pass CBR” rate-control mode, then does having more buffers enable the encoder to optimize bitrate over a larger section of video? For example, if I initialized the EncodingSession with “gop_length = 30 frames”, would allocating 30 IO-buffers give me the best possible result?