you would have a QBI loss caryover which would be used to offset future years' QBI income. so your net QBI deduction could be reduced in the future. However, the QBI deduction is set to expire in 2025 unless Congress renews it. another question is say you have income from rental in the future. could you argue you can elect safe harboer in that year to take the deduction having passed on it in loss years. safe harbor only means if you meet the criteria the IRS can't challenge it. the reverse is not true. Depending on facts and circumstances the IRS could are you had QBI losses even though you didn't meet the safe harbor criteria. so it's really your choice.
