This is just adding unwanted complexity to an otherwise simple problem. The purpose of a distributed cryptographic ledger is that no authority may commit to it

This is just adding unwanted complexity to an otherwise simple problem. The purpose of a distributed cryptographic ledger is that no authority may commit to it without the required cryptographic private keys. If you have some party who can commit to the ledger arbitrarily, or who has a skeleton key, then you don't need the distributed ledger - you just need a centralized ledger with replication (far more efficient). Any situation where ownership is enforced by a central party is a poor fit for this technology. You either want the cryptographic keys to secure the property, or you want the humans in charge to secure the property through a legal system. There is no sensible marriage between these systems. A system controlled by humans undermines cryptographic security, and a system controlled by cryptography obsoletes human control. Therefore, the only thing worth owning w.r.t a digital ledger is the digital token itself. As a proxy for anything else, a digital token cannot assert right of ownership.