In this initial release of SIOC V2 in vSphere 6.5, there is no support for vSAN or Virtual Volumes. SIOC v2 is only supported with VMs that run on VMFS and NFS datastores.
When applying an IOPS limit rule to an object within vSAN, the vSAN I/O scheduler will “normalize” the size in 32KB increments. This means that an I/O under 32KB will be seen as one I/O, an I/O under 64KB will be seen as two I/O, and so on