My suggestion is to allow any graphics set to display in a custom window to do so without affecting the main graphics window and vice versa.
Also allow us to define if we want an image to display in the text area only, even if the graphics window is open, this could just be an extra parameter thats on or off. It would be great to be able to have 1 image in the text area, another in the graphics window and also another one in the custom window at the same time.
Currently if you have main graphics window open and you want to display an image in a custom window, it will put the image into the main graphics window.
This is very restrictive. An example; You use the main graphics window for a general wide shot location image and you use a custom window to display a character portrait or a blueprint layout of a location or a prop such as examining key evidence item. Or you want a hand drawing of a custom map, or an image depicting the weather etc.
Also how it is currently, if you turn off the graphics window so you can get around this, and have the main image display in the text window and your other image in the custom window. This can be ruined by player who might inadvertently turn on the Graphics window for preference not knowing it wasn't what the author intended. I guess for now we will have to state this on the first screen/intro.