Yep, When max lift is covered by 6+ degrees, where is the true centerline. Then throw in assymetrical lobes... ugh.
That's why I like the Find max lift, then get readings coming up to the top and down the backside at .050 before and after max lift. Makes the math easy. Add two numbers together and divide by 2. Done. Don't have to worry about adding/subtracting opening and closing events, btdc or after tdc +180 nonsense. KISS method.