- When you name a device, LastPass should remember that given name even once signing you out. If it has the same device unique identifier, why would you not auto-fill with the previously entered name?
- Retyping my device name once a month means I stop doing it, which lowers total security (pic below shows how silly it is).
- Why not also store the devices unique identifier in trusted devices and the last few IP addresses? If someone can write ANYTHING into a device name box, then it's trivial to pretend one device is another.
Example from Unity, which supports unique identifiers across all platforms: https://docs.unity3d.com/ScriptReference/SystemInfo-deviceUniqueIdentifier.html
