Better shadow detection to prevent false positive / out-of-zone motion alerts

I have motion zones set up to explicitly exclude the relatively busy sidewalk in front of my house. However, when the sun is low on the horizon, pedestrians on the sidewalk cast a very long shadow that reaches into my motion zone and sets off an alert.

A possible feature here could be to enable varying motion zones based on time-of-day, but that sounds hard to manage as the time configurations would also need to be updated throughout the year as the sun sets earlier or later.

Seems like better shadow detection is a much more elegant solution here.