When Le Forge says it’s gonna take 16 hours to fix the engines, he isn’t working that whole time right?

It means there’s a team working on it during the entire time, and it’s not useful in any way to increase the team size. They also talk a lot about how that time is buffered.

In an emergency it would make sense to make people work for longer, so maybe there’s some rescheduling implicit on it. But they never make it clear.