How to create a Hyper-V vhdx with "Bytes Per Physical Sector" = 512

I need to create a volume with "Bytes per Physical Sector" = 512 so I can use it as the staging location for Backup Exec (using GRT -Granular Recovery Technology) to restore Exchange (physical 2007) mailbox / items. (I know this setup is old. We are migrating.)
GRT requires the staging location have the same sector size as the volume from which the Exchange log files were backed up.
 
To do that, I added a new VHDX to the Backup Exec server (a 2012R2 VM on 2012 R2 Hyper-V host) and then I issued  
"Set-vhd VHDname.vhdx -PhysicalSectorSizeBytes 512"
to change its Physical Sector Size to 512 bytes. I did verify using "Get-vhd VHDname.vhdx" that it shows PhysicalSectroSize = 512.
But to my surprise when I got in to the VM and issued the following command on an elevated command prompt:
fsutil fsinfo ntfsinfo D:  (where D: is the VHDX I just created)
it shows the "Bytes Per Physical Sector" = 4096

I'm confused... Why are they different? Did I miss anything? How to create a vhdx with "Bytes Per Physical Sector" = 512