VIO uses cloud-init with the metadata service just like any other openstack. If you want this on windows there is cloudbase-init.
Introducing the Metadata Service - OpenStack Blog for VMware - VMware Blogs
Is there an article that talks about normal OpenStack KVM images will not work in VMware Openstack? From what I know these formats are converted to vmdk on import. If the guest OS has the needed drivers then the image should deploy and boot. True the formats are unsupported but the images should still work if everything needed is present.
Import Images in Unsupported Formats by Using the CLI
Building from and ESXi platform ensures that the proper drivers and settings will be present. Then import to VIO if in the ESXi host is in the same vCenter or export to OVA and import if the build host is not in the same vCenter.
Import vSphere VMs into VMware Integrated OpenStack
While it is possible to build and or use images from other platforms as long at the drivers are present before converting.
OpenStack Docs: Converting between image formats