I'll point out that temp score is no problem - you never use the sound from the final cut when doing this kind of thing. Just the picture.
Alternate takes, yeah, that's annoying when they're similar. A good example is the Dr. Evazan scene in Deleted Magic. All alternate takes, so very little of it is color.
Still, a composite cut is great because not only can you see as much as possible of it clearly, watching it you know exactly what's different. =) You become a scholar even when you're not paying attention.
Anyway, excited to see this.