This is a secondary function, as far as I remember you would need to explicitly mark you item as lost and it can only connect to app running, not really a mesh network of tiles. In any case, I think I should be able to use it locally, if I want to opt in for network, then signing up makes sense.
Your proposed use-case won't overcome their business model. Their business model (theoretically) makes their company more valuable the more users they get (users that cave).
