That's... all the time!
I think I will not try to have a full script anymore, at least not for the kind of project I'm doing right now with my comic (long-form, lots of subplots).
First I thought that BECAUSE it was complex, I had to have a strong script to avoid plot holes.
But finally, I'm changing so much things on the way that the script becomes a burden.
The most extreme case, but many other cases happened: recently, I decided to remove two chapters to make a sort of spinoff with them. But I want to have them reintroduced into the main story when this is all finished. Which means
- having the side comic stand properly by itself
- having the main story not suffer from the (temporary) loss of two chapters
- having the main story with chapters reintroduced not have too many redundancies:
-> script entirely reworked!
Now I only do mindmaps. They are great for avoiding plot holes and giving you enough freedom.