I think they are related to the OS in the same way that the Judgement is related to the MC, as in, that is usually how the author chooses to express things.
They define a landscape that the whole story operates in, not just the OS. If they didn't, we wouldn't see Action drivers being so confounding to Be-er characters or Decision drivers muddling up Do-ers so much. But there is palpable outcome when you do this kind of thing.
But the drivers must also be out of sync sometimes with their stories -- if the OS wraps up before the MC throughline, isn't it necessarily true that the last driver happens before the MC throughline is over? (Or is it just that the climax has come and gone before the MC throughline has been wrapped up?)
I haven't thought through this example, so... let's call it an open question: When Cole says "I see dead people" -- this transitions all the storylines from one act to the next, doesn't it? And if it doesn't, then which throughline would you put it in?