You would have to have a contract that gives you claim on these other assets. I would guess that those kinds of contracts are very rare, because you’d no longer

You would have to have a contract that gives you claim on these other assets. I would guess that those kinds of contracts are very rare, because you’d no longer be buying gold but a derivative whose value derives in part from gold and in part from the other assets of the company selling the contract. I would bet that in practice buying gold plus a corporate bond would make a reasonable, simpler and more flexible substitute for said derivative, making demand for the derivative basically zero.