Hahaha it's hard to get two M3 owners to agree on anything. Then again there are a bunch of threads on ruined front PS2's.
If you start at 28psi before the tires get hot and overdrive the car,you can get some serious sidewall flex that might lead to excessive tire wear on the outside shoulder.
So it might be better to start close to the target psi and go down as required.
Any ntelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction.
E. F. Schumacher