Don't understand why?

[racingbmwm3]

Engine adaptations (fuel injector timing/duration, lean/rich mixture settings, spark plug timing, VANOS timing) are always being adjusted to reach optimal performance. They are only ever changed once the O2 sensors are at operating temperature. This takes longer than 25 seconds. They are also slowly adjusted, its not an on/off switch. Resetting them to all 0s doesn't speed up the process. The engine still has to adapt itself either way. Having done dozens of of diagnostic tests involving adaptations, the shortest I ever saw the values start to change was around 15minutes. It still takes 30min to a couple hours for them to fully stabilize.