Since many photos don't include captures of most of the sky, why not have an option for the user to "assume sky". In other words, use the color at the upper edges of the captures to make a sky of the same color.
The computer would then blend differing colors together where appropriate. Hmmm.... This is harder to explain than I anticipated. Hopefully I made myself understood.
Great idea! The simplest words: the lack of sky should be added by MSR ICE. It would be great, because even if I capture the sky, I can't combine it in ICE