This seems to be a recurring theme in many projects, so I’ll put some initial thoughts down now.
In writing, there seems to be two tendencies: Outlining and ‘Pantsing’. This is a long-running binary in the writing community, and I think it falls under this category.
Ed Catmull argues that, in Pixar, they found that “Just Starting” had a substantially better outcome than deliberate planning. Especially since lots of the development process for a film was essentially “iterating” on the story / dialogue / animation until they had it right
If you spend a lot of time making a detailed plan, trying to account for everything (which is impossible), then it’ll be harder to be quick on your feet should you come across a problem
This might be a little different in writing, given that you’re creating the story yourself and thus any unexpected events would just be your own whim (probably)