I haven't done that much incubating, but I'd say "lockdown" should be applied mainly at the point where the first eggs have pipped, since they will be affected by humidity changes a lot more at that point. And I think it's probably okay to stop turning after day 18 or 19. I don't really see a point in always boosting the humidity at day 18, especially if you have no idea what the weight loss has been. Tracking the weight is the best indicator of humidity requirements, in my opinion. But I'd see Sally's guide as more of a starting point, from there you have to figure out what works for you.