There is no way that would work with the IRS. Anything you estimated and can't provide documentation for will automatically be considered void and non-existent

There is no way that would work with the IRS. Anything you estimated and can't provide documentation for will automatically be considered void and non-existent by the IRS if that thing reduces your tax bill. If you think you have about $5k in valid deductions, but you can't provide any documentation upon an audit, then that $5k will be reduced to exactly $0 and you will owe all additional taxes plus interest and penalties.