> I'm guessing this is Google similarly trying to stop people extracting their local models by not letting unlocked devices access them.

It seems like it's not even that thought out. Google allows the devices to fully download the models...just not run them?

If you want the models, here ya go: https://pastebin.com/jh4YG5jX

That's every file the app downloads on launch.

EDIT: Seemingly I'm wrong. Someone below in another comment stated that they are not allowing the device to download the Gemini Nano model and that's what the failure is from.