Often I don't have a good enough mobile internet connection. But I like to do edits on my mobile devices.
So the option to store "smart previews" locally is great.
But it does not work if I have original files in the cloud, then it will just download the whole files with the "store locally" option. And yea, most mobile devices don't have much more than 1TB available and it's just not always necessary to store the 50 megapixel raw files on the phone.
So having a choice when hitting that "store locally" button between "download smartpreviews" or "download originals" is a must.