After the system is installed, the photo viewer still exists and must be manually set to default.If a setting is greyed out that is because you have selected the component it relates to to be removed.
The first xml, Photo Viewer - not marked as deleted or pre-deleted, I can set Open - Photo Viewer。That tweak actually depends on the 'Photo Viewer' component, make sure not to mark it for removal or remove earlier.
OK, so I loaded 1903 and your preset, attached is the picture of the Setting.Help me test