The boots do use the default DS shader and textures, but the CR2 exporter doesn’t try very hard to export materials as I recall - the assumption was, at least as it was originally made, that it would be used by content creators who would produce their own materials for Poser and DS. If the names aren’t clear you can use the Surfaces pane in DS to show you which texture goes where and rebuild the settings in Poser.
You don’t get a chance tos et UV Set as the boots have only one mapping - most items will not use multiple UV sets.