IQ testing gets a lot of flak because its usefulness is misunderstood and overstated, and because historically it has been used by adherents of scientific racism.
I get the sense from the comment about BMI and "axe grinding" that you're really trying to make a dig at what conservative leaning people might call "SJWs". If that's the case, you're doing yourself a disservice by letting ideology obscure the very real scientific problems with IQ testing.
Only against the advice of most accountants. Exchanges between different grades of the same precious metal aren't considered like kind transactions, so it seems pretty unlikely this "trick" would work for crypto.