Rebirth changes the shape of a Fan per Step run: you give up some current progress to gain a multiplier that accelerates later progress. The creator's official description confirms the multiplier benefit, but our evidence packet does not contain a stable cost table, reset list, or exact new multiplier for each rebirth. Any universal 'rebirth at level X' answer would overstate the data.
Use a readiness checklist instead. First, open the live rebirth panel and record the requirement and reset warning. Second, confirm that your equipped Play Button and accumulated Fan boosts make the early level range feel repeatable. Third, finish any near-term 10-level Fan milestone if losing that progress would be frustrating. Finally, compare your next objective: a gate may be closer than the rebirth payoff.
Reported gameplay described Golden World requirements involving 10 rebirths and level 100 after rebirth, plus large Fame and Wins multipliers. The narrator also said the combined Wins math was unclear. Those observations can guide future testing, but they are not strong enough to become a current requirement table or break-even calculator.