There's no point using a block chain to represent physical objects. By the time you have a physical entity managing the said objects, you're better off using a more efficient distributed database. What happens if someone steals a given piece of gold for example? How do you update the blockchain to reflect that? There are many other ways in which the database could become corrupted and no longer correctly represent the physical reality of the gold store. You don't need a (somehat) slow, power hungry, decentralised, immutable, consensus mechanism for this.
In the case of bitcoin, the proof of work blockchain system works because the tokens just represent themselves, not some real world physical object.
Disclaimer: I only read the summary and not TFA - and no nothing about this project. It just looks like the usual buzzword publicity to me.