i just bought a 256GB iPad Pro, and have iCloud Photo set to download originals to the device (not "Optimize Storage") ... Unfortunately, the iPad doesn't actually download anything other than a preview thumbnail unless I view the images, one by one. This is in contrast to Photos on MacOS, which actually downloads full-res EVERYTHING if you tell it to. 
Does anyone know how to force the iPad to download all photos and videos without having to view them all, one at a time?
Does anyone know how to force the iPad to download all photos and videos without having to view them all, one at a time?