LEDzZzEPP: I don't think change the image of one sky in some courses can cause ''instability'', its a static image
No problem with the suggestion but, as a long-time veteran of software development and beta-testing, any change might cause a cascade of errors! Too many times I heard a programmer tell me that a recent change could not possibly have caused an error - and then found said error (and others) were caused by the recent change. (Did a few myself!).
In reality, I doubt WGT would consider this (and many other suggestions) unless there was a payback. You know, like selling different skies the same way they do effects! I can see it now:
Clear skies : 50 credits for 200 shots
Partly cloudy skies : 40 credits for 200 shots
Mostly cloudy skies : 30 credits for 200 shots
Add thunder and lightning : 20 credits for 200 shots