I can tell you a little trick, which could be a work around for now, until more is possible being programmed by the Vue producers.

If it doesn't bother you, to have the same landscape infront your clouds like in any atmosphere icon image, then do the following:

render your sky with your camera setting, make sure the sky and clouds, the way you want them to be seen, is in the upper 2/3rd of your render (you have to experiment a little for the perfect position.

Save your rendered image.

Then by double clicking on the camera in the browser window, open the advanced camera option window.
On the bottom right is a button called 'Background'.
Click it and a small window opens, where you can load a bitmap image, in this case your before render of your nice sky and camera tilt.
OK this window, OK the camera option window.
Now save your atmosphere and what you will get is a atmosphere preview image with your rendered image filling the sky background with the usual landscape infront.

That's the only thing you can do right now, to influence the outcome of the atmo preview images ...