The reason I ask about the trigger point is because, in your pics, the AEM gauge shows a much steeper ( almost brick-wall vertical ) slew rate, entering the display range. So, it likely spent less time between the gas change and the 1st deflection on the analog signal. In the 2 pics I posted, the purple line is the solenoid switching. There is about 12ms from solenoid to the 1st deflection for both the AEM and LC-1.
In my pic, the "dip" is lambda 0.865 with a gas of 0.885. ( it varies with the gas pressure ) So, it is possible that the V2 has less error ( < 0.02 lambda ) over that period, as long as it is not still showing the higher gas value, at that time. Maybe I should get one to play with
Looking again, the AFR500v2 seems to be going rail-to-rail, all the way from 5v to 0v? So, it couldn't overshoot, if it wanted to ? What are the gas values ?
i.e. the stabilized value is the 0v rail (ground).
Rough eyeballing it from the AEM trace, it looks like the rich gas is about lambda 0.7? Is 0.7 lambda = 0.0v on the output of the AFR500v2 ?