Thanks for letting me know. NodeCanvas indeed does use the OnAfterDeserialize to deserialize all things that need deserialization (graphs and blackboards more specifically).
Unity has a bad habit of changing critical things like these. I also don’t know if Unity changing this was intentional or a bug, but to me it seems un-intentional, since keyframe[] should be possible to access like most other “normal” API can.
I will try to find an alternative solution (probably with a reflection hack) to get this working, or maybe Unity changes/fix this in a later version.
Is it possible for you to remain on your current Unity version? If not, let me know and I will take a look at this sooner for you.
Thank you.