This is a desktop so I think the assumption is that the savvy can attach a USB3/4 device with appropriate storage (e.g. for your massive photo library - it's easy to change the location).
Except that storing your iCloud Photo Library on an external drive is a PITA, as multiple daemons (photoanalysysd being one of them) will randomly activate themselves to do their shit, making it difficult to predict when the drive will not be able to be gracefully ejected. It needs to be a permanent external disk.
