P: Download all smart previews automatically

I've started using my iPad to do my initial round of rating photos when traveling, and I'd love to have the option to automatically download smart previews for my entire collection. This way, if I have an intermittent internet connection (or none at all), I can continue to go through my workflow effectively. At the moment, this works great if I have a fast and stable internet connection, but unless I've already clicked on each individual image, I don't have access to the full resolution previews when not connected to the cloud (i.e. on an airplane).

I'd love for this to be an option on both mobile & desktop apps, and allow people to choose the current behavior, download all, or set a storage limit.

Thanks!