It is little complicated because the noise texture of clouds contains precomputed ray marching informations encoded on each channel. It is important for calculating clouds density and scattering.
I can think of an alternative mode of rendering clouds, but it would be very limited for shading.
Pre rendered 3d shape into texture will need additional displacement mapping to look properly.
If you have any textures that you would like to use on sky then send me and I will do some tests and show you results. 