The only legal thing you can do after the first of the year to "manipulate" the bottom line is in the assets section of the Sch C. You can choose to NOT take all or part of a 179 deduction, elect out of the bonus depreciation, depreciate assets that could be expensed instead of expensing them and/or use a longer depreciation period.
https://www.wolterskluwer.com/en/expert-insights/use-expensing-or-bonus-depreciation-to-write-off-as...
