Man this sucks. I swear Samsung is making Art Mode as hard as possible to use outside their locked in controls so that more people will pay their dumb subscription.
Personally I use my Frame for displaying my own work as I am a photographer, and I was really hoping there might be a way to control things like brightness/color temp of art mode, as well as single photos/slideshow or even change the photos through HA but looks like NONE of this is doable because Samsung are jerks 