>I'm looking for legitimate ways to sell Bitcoin in the future.
No crystal balls here. Whatever the method is, is exactly what that is to you, in your region.

>Maybe a tax loophole.
Public Ledger.

>Does anybody run it through a corporation somehow?
Public Ledger.

>Friend or family overseas and then back in dollars? 🤷🤷
Public Ledger.

>People avoid tax in fiat world all the time.
Public Ledger.

>Surely someone smarter than me has figured out how to do it legally with Bitcoin self custody.
Public Ledger.

>Or not.
Public Ledger.

>Maybe one day.
Public Ledger...?

An Atomic Swap into a more private coin is what you're looking for as a solution today,bthen you can transact accordingly.

Or just wait for BTC to offer a similar feature of privacy, when it does, probably?

No other options here, friend. Sell and report, at least for now!