Consider a new coin called USD (or perhaps Digital Dollars or Electronic Dollars DDR or EDR). Perhaps a 2nd new coin called Physical Dollars (PDR or PDL). Some thought might be given to Pennies, Dimes, Nickels, Quarters, etc.
What does THAT do for you? On a 1 to 1 basis, you could track every single dollar created by the Fed. Each digital dollar would be identifiable and unique. An end to digital counterfeiting aka a bank or other entity creating an accounting entry that misrepresents the number of dollars in existence.
I'm answering myself: Why needed this kind of digital dollar. To not give more the possibility to the FED to do monetary policies. To not have more the possibility to print paper dollar every time will be in need for money?