That's cool! I am looking at this and seeing another issue with AirTag: I actively use the feature on Tile where I can use the Tile on my keychain to find my phone by pushing the button, and I guess AirTags is entirely missing that feature.
Apple not allowing 3rd parties use of their proprietary technology is not the entirety of the DoJ’s argument. For example, their claims about Messages and Apple Watch are about support Apple hasn’t built, not about what they prevent 3rd parties from building.