It’s not easy keeping power in a specific zone. Even a small hump immediately raises my power to z3/z4. Even if I adjust my cadence and gear, it’s hard not to hit z3/z4 a small amount of time. The same can be said of not hitting z1 downhill in a endurance ride. Displaying a 3 or 10 seconds average power, also contributes to not adjusting the power fast enough.