Hi again,
I can definitively understand why you’ll want to re-render the whole scene if you changed the light setup.
As Corune said, thank you so much for the little tutorial about shape keys, I will try and see what I can do with it soon 
. It is a really well explained tutorial, I don’t think I’ll have any issue following it.
I am struggling to find inspiration right now, it’s been a month since I did anything new (the last one was the 24H bowling challenge). I am looking for new ideas by wandering in the forum 
. And your tutorial may be a new field to explore. Who knows, maybe I will create something new by the end of the week ? If I do I’ll tag you in .
Cheers !