It is my understanding that for a "plain vanilla" rental property one is unlikely to qualify as a business and therefore would not be able to claim de minimis election. That is because one is unlikely to spend 250hrs/y actively managing single-family rental where tenants tend to stay 1y+.
YOu are confusing the safe harbor di minimis deduction, with the requirements for the QBI deduction. To take the QBI deduction, the 250 hours "directly involved" rule applies. It does not apply to the safe harbor deduction.
