Well I certainly can't blame you for worrying about precipitated withdrawal.
Honestly I don't actually know that much about subuxone, but as I recall, it's best to use the clinical opioid withdrawal scale (the cows) to determine when to take the subuxone. Sorry I don't remember exactly where on the COWS you're supposed to be before starting subuxone to avoid precipitated withdrawal, but I'm sure Google can uncover that information pretty quickly.
COWS is better than just going by an amount of time since last use because it's a lot more objective.
As for how much you should be on, it depends on your habit (which due to regional variability I can't tell from what you've mentioned in your post). I seem to recall that the general practice is that once you're high enough on the COWS to begin, you're given something one strip or tablet every half an hour until your withdrawal symptoms are gone. But this might be worth double checking with Google too.
You might well find that the dose that removes your symptoms when you first start might not be enough to completely suppress cravings after a couple days, if so you may need to increase the dose. Depends on your circumstances of course, but just something to be aware of.
Sorry I can't be more help, I've never been on subuxone. I looked into it when I decided to get off heroin myself, but ended up going with methadone. So most of my knowledge of subuxone is based on stuff I learned a while back. I wish you luck though!