all the QBI safe harbor means is that if you ACTUALLY meet all the stipulations then the iRS can not challenge the QBI deduction. The IRS can ask for proof that you in fact meet all of them. if you do not then there could be issues because you in effect would have committed perjury. if you took a QBI deduction but don't qualify or don't elect the Safe Harbor election then, if audited, IRS will see if you meet the 199A definition of a QB.
