vfio-pci.cfg not stubbing all devices in IOMMU group

My group 24 looks like above. With BIND=0d:00.3 in vfio-pci.cfg, 0d:00.0 0d:00.1 and 0d:00.3 all show "Kernel driver in use: vfio-pci". But 03:08.0, which is in the same IOMMU group, shows "Kernel driver in use: pcieport".

This is fine, probably preferred behavior, but it doesn't mesh with the documentation I've seen from @limetech:

Quote

In addition, and importantly, this script will bind not only the specified device(s), but all other devices in the same IOMMU group as well.  For example, suppose there is an NVIDIA GPU which defines both a VGA device at 02:00.0 and an audio device at 02.00.1.  Specifying a single device (either one) on the BIND line is sufficient to bind both device to vfio-pci.  The implication is that either all devices of an IOMMU group are bound to vfio-pci or none of them are.

Is it more accurate to say that all functions of a device in the same IOMMU group will be bound? I realize with ideal/typical IOMMU groups that should mean the same thing, but is not in this case.

Any clarification on the expected behavior would be much appreciated.