The maximum sample rate for SF Pro 12 PCM files is 384kHz. I don't think that or higher is needed for anything other than scientific measurements (and canine users).
How about When using Neutron and Neutron 2 Like in CuBase Pro Have Neutron Actualy show more than 2 chanels in Sound Forge ? For Example When Sound opens a file More 2 channels Using Neutron or Neutron2 Have work with Neutron's Advanced Surround Support.