for that to be implemented you would have to prove you had that coin on a wallet for X amount of time, if not it makes no sense for most "normal" people (not counting billionaires or corporations).
You could make an argument that Hive could be a "USA coin" but lets say it is not. For example i earned 500HBD last month and i want to cash out. I could use LeoDex, swap it to "official USA coin" and right away make a transfer to cash it out, and keep it all.
But from my understanding the idea of Born in the USA coins is that they know who the main guy is, who can control it and then they don't even need CBDC. And Trump does not want to pay taxes on Trump Coin 🤣
It has nothing to do with an individual's coins, everything to do with the underlying network/project. If founded/run from the USA from whatever metrics they end up using, then its users in the US would be exempted from capital gains.
Actually this massively simplifies reporting. Right now you have to report every single transaction for gains and losses, including swaps and spends. A capital gains exemption of any kind would make this not necessary.