When you add an image to a HoudahGeo 3 project, HoudahGeo stores the image's preview and master path. The preview image is used for publishing. During EXIF/XMP export you get the option of tagging either the preview or the master image file.
The problem is that HoudahGeo fails to look up the master path for images referenced from a remote file server. It thus uses the same path for both master and preview. Hence it will tag the preview file even when you check the "Tag Masters/Originals" option.
The technical explanation: Aperture stores an ID for the volume where the image is located. HoudahGeo derives a file path from that ID. This works only for local volumes. I spent all day looking for a way to perform this operation for remote disks, but have found none.
As a workaround, you could drag the images from the Finder into HoudahGeo. HoudahGeo would then only reference the master files. This is actually all that is needed for EXIF/XMP tagging.
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