I understand your problem. I'll follow the topic to see the best solution.
I think it would be useful to have access to something like this in the script:
ImageView1.Bitmap = LoadBitmap (File.DirAssets, "resolution1\someimage.jpg")
...
ImageView1.Bitmap = LoadBitmap (File.DirAssets, "resolution2\someimage.jpg")
Maybe this can not be implemented.
I created an imagegallery class and I have several icons in it. The icons are initialized depending on the resolution of the device.
I believe that for large images this is not a good solution.