However, even ALPR doesn't show any devices for me:

I'm glad citizens in the EU are more on top of this. I really wish we as USA citizens had access to the same database of GPS coordinates for each Blink, Ring, and Amazon Key device that police do. Does anyone know how/if something like that could be FOIA'd? This seems it would be particularly fruitful if FBI/DHS has a comprehensive dataset for the entire nation.

Though I do worry that they may not "have" the dataset, but rather just have "access" to it via a queryable Amazon/Palantir database/API.