Thanks!
I tried to give the guide a good level of AF info so, depending on your needs, it constant alone. However, the AF guide does dive deeper into the AF system and really is as much about sharpness as it is the AF system. Kind of a one-two punch. So, it does have a lot more info in it.
I'll be updating it for the Z8, however, from an AF system standpoint, there's really no difference. Both camera's use identical AF systems and my recommendations for each are the same. So, for now, anyone with that guide can apply everything I say about the Z9. The update will basically be to change "Z9" to "Z8/9" throughout the text