When to add a second platform: after the primary has cleared 90 days of consistent broadcasting, after the primary's metrics show signal is established (rising followers, rising CCV, rising engagement), and after you have the operational capacity to run a second cadence without compromising the primary's consistency.

The 90-day milestone is the structural gate. Below 90 days on the primary, adding a second platform splits the limited time and attention you have, which weakens both. Past 90 days, the primary's systems are operational and the incremental capacity becomes available.

The signal check is the second gate. Even past 90 days, if the primary's metrics are still flat (followers not rising, engagement not building), the diagnosis is usually that the primary itself needs more focus, not that a second platform should be added. Adding a secondary while the primary is unstable produces two unstable platforms.

The capacity check is the third gate. Honest self-assessment: do you have the production hours to run a second cadence reliably? If not, wait. Build capacity first. Add the second platform when the math is sustainable.