Is it possible for a 4 screen video wall to cycle from a unified image and separate images per screen?
That is possible, but there’s no package that supports this out-of-the-box. You essentially have two options right now:
For images spanning all 4 screens, you’ll have to pre-split them into 4 individual images. Then use (for example) the video player package, create a setup for each screen and assign both the separate and pre-split images to each playlist. Make sure all 4 playlists have the exact same duration and the result will be synced.
Combined the 4 individual images into a single big image and use a single video player package based setup. Of course then reduces the possible resolution on each screen to 960x540. Depending on the content, that might look bad.