In spite of your estimation of inflammation being the most likely cause of Alzheimer's there is no agreed theory of this disease - although it's becoming more and more clear that the currently agreed symptoms (amyloid and tau) are not the causes.

Agreed that it's a possible cause, also agreed that brain inflammation is bad (speaking as someone who nearly died of a strep brain infection).

But it's also clear that what's diagnosed as Alzheimer's is the end stage of a process that most likely started in middle age. My own inclination is that it starts with insulin resistance in the astrocytes, which would explain the increased risk for people with T2D (both striated muscle and astrocytes, the cells the neurons depend on for glucose metabolism, have the same kind of glucose transport mechanism). T2D is a cascade that begins with gradual inactivation of that receptor's response (in striated muscle) to insulin.

To be fair to the inflammation causation hypothesis, T2D does increase inflammation through the body, so that could indeed be the root cause in the brain

Fortunately, the interventions you mention for people not yet diagnosed, intervene for both inflammation and insulin resistance work no matter which hypothesis turns out to be correct.

Personally, I'd hesitate to recommend any particular treatment for people already diagnosed, although increasing brain plasticity isn't bad; also anything that boosts BDNF.

Not bio credentialed, just got interested when my mom was diagnosed decades ago; have been digging though studies since then.