I think all existing, and yet-to-come, "bitcoins" need to be taxed at capital gains rates to US citizens.
The U#B needs to be unique in this way. That is why the underlying floor, privacy, inability to "print"/treat as fiat, and LEGAL TENDER (non-taxibility) aspecs of the U$B are essential. You want this thing to work and be a huge net benefit to the middle class American citizen.
Privacy could doubtless be further improved by incorporating some of the stronger privacy protections I understand exist in more modern alternatives (https://www.investopedia.com/tech/five-most-private-cryptocurrencies/) like Monero and Zcash.
Then essential thing is the chain code be open source and not under control of the US government, except for protection of the integrity. And, of course, no government -- certainly not the US government -- is "your friend".
Governments are psychopathic by nature, and that cannot be changed. If the last 100 years of freedom connivance has taught us anything, it should have taught us that: THE government is a drunk gorilla, "a terrible master", and those who want to "make a career" of working for the US government (or any government) need to be identified early and kept, along with the drunk gorilla, on a choke-chain of razor wire.
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