Turn the current tax code upside down, and you get...
a hernia
The current tax code is 70,000 pages long. People are worried about "the devil in the details" of a plan you can hold in your hand (999), but they aren't worried about the devil in the details of the 70,000 page tax code?
The IRS now officially refuses to gurantee any tax advise they give you is correct. You can be sent to prison for not complying with the current 70,000 page tax code, even if you are following the IRS instructions to the tee.
That's the "devil in the detail" I'm worried about.
The vast majority of Americans don't have to botther with all those nuances, because their returns are simple unless they start making over 100K.
Above that, the more you make, the more complex things can get.
But if you make that much money, you hire a pro and it's his problem, not yours.