I have recently watched hours and hours of footage of B&M hypers and I have gone on as many as I can. What I can tell you is that the hypers/giga coasters (Leviathan included) don't pull more than 1G when they are rolling more than 10 degrees. If you want to watch footage to see this, you can watch Leviathan, Nitro, Goliath at la Ronde and all of the hypers. There are some built in the early 2000s and 1990s that are not as well done as the ones that are created now. Give me feedback if I'm wrong. This should be part of B&M's formula and these rules don't apply to Intamin at all. If you are making a turn, drop the normal force to 1G or less then start the roll, don't start the roll then drop the forces. This may take a bit of getting used to but it's worth it!
Good Luck, Andrew.