Allow dialogs to be used as a source for render to texture on objects in game. This would allow for easier, more customizable interfaces on many vehicles, including better/easier to make MFD in aircraft, displays for components in land vehicles, etc.
Nothing fancy, no need to add in things like buttons or drop downs, simply being able to draw to the RTT surfaces simple things like text, images, and basic shapes would be enough to do everything that could be imagined. This would be an incredibly powerful tool for the community.