Dang. I somehow missed the .atlas property on all exSprite instances. This can clean up the use of the Resources.Load() method i'm currently using to get an Atlas. However, you would then be limited to only changing the sprite to another in the current sprite atlas.
I'm not sure if i'm going to change how it works or not. I need to get some more use out of it to see if this is an issue or not.
I suppose i could also create a new action which would change the atlas the sprite used, or, using the current action, check to see if you include a name in the 'Atlas Name' property. If not, it uses the one in the .atlas property.
That might be the best bet, actually.