I have a device, Ross-Tech Hex-Net, that is a OBDII device used for diagnosing VW and Audi (and others in the VAG family). My USB filter for this is simply the vendor id (0x0483). The reason for the coarseness of this filter is that the device first will appear as a HID device. If firmware on the device needs updating, the vendor software, VCDS, will expose the on-device flash device as a storage device. Having the filter set to capture at the vendor id allows the Windows guest to mount the flash device and do the update.
This all works in 6.0.4. Starting in 6.0.6, the expected behavior is broken. When the guest mounts the flash device, it will hang and the host (MacOS) then mounts the device. The guest hang can only be cleared by killing off the VM.
Looks like a bug.