The obvious way to get around the need for this feature is to create a sprite at screen resolution, that always faces the camera, and that fills the whole screen. When it comes to scaling, I do this:

sprite.scale_x = ftan(camera.arc/2,distance_from_camera*2/camera.size_x);
sprite.scale_y = (camera.size_x*3*sprite.scale_x)/(camera.size_y*4);

And I notice that it has a curiously high margin of error. Checking the documentation, I see that scale_x and _y can only range 0.01..100! I get popping as the image tries to scale to the size of the screen at different distances, my layers of sprites never quite align, and I never get the sweet clarity of an image displayed at its native resolution, 1:1.

Camera-independent images in the level are the preferred solution, but increasing scale precision might work too? I look forward to features like this that will make 2.5D games easier to make.