One, the confusing narrative around blockchain. Settlements don't require any kind of "proof of work" mechanism. It's basically a shared ledger where only permissioned parties can access/write. Some are calling it "Distributed Ledger".
Surely, someone is going to point out that "proof of work" is not the definition/requirement for blockchain. But, using it interchangeably and confusing the bank "blockchain" with the cryptocurrencies "blockchain" is causing the confusion and euphoria.
Second, settlements don't even need "coins". Cryptocurrencies use "coins" as an incentive mechanism. In PoW, you earn coins for securing the network. In PoS, you stake your coins to secure the network and earn fees.
But, if you have a permissioned, private blockchain there is no need of "coins" because there is no incentive structure. Will DBS earn extra coins for each transaction in the blockchain because of staking or something? If not, then these "coins" are just numbers to enumerate position sizes. In which case, why even call them "coins" and not "settlement amount in x currency"?