Regardless of whether or not you think a US CBDC is a good idea or not, if one is implemented, what will the technical[0] details look like?
[0] I mean from a computer science standpoint more than a financial one, since the latter lends itself to endless macroeconomic debate.
When you get into a CBDC, you're probably looking at a lot more real-world infrastructure needs than even the most ambitious crypto. In particular, the on/off ramp capacity has to be huge, especially in early phases of the evolution when you're going to run into random commerce opportunities that aren't ready. (Vending machine that only takes 25c coins? Kids selling Girl Scout cookies?) People are going to need to get notes and coins in and out of the system.
I could see having it farmed out to a cooperative of the major private banks, like the Federal Reserve is nominally. This fits the grand American vision of privatizing things that make more sense as a public good. But also because they already have infrastructure and footprint. If every branch/ATM of the 10 largest banks in the country is a CBDC access point, you can make it viable for normal people quickly.
If we treat it as a platform where the banks talk to it, rather than mere mortals (again, appealing to regulatory capture visions), it means that the ledger is basically "authorized parties only", so you largely don't need a blockchain model. You probably just have mirrored infrastructures at each major bank, streaming updates between each other with a tight SLA.