Great post!
However, having published literature on AD, there is actually a better "test"
10 years before we see any problems with amyloid and tau, there is glucose hypometabolism in the brain. Meaning not enough sugar or energy is getting to the brain.
You can test this and have a 10 year window before disease starts.
Alternatively, you can also rest peripheral glucose and insulin. Once those are elevated, there is cerebral glucose hypometabolism.