customer.io: sync historical data

[jurajmajerik]

Is your feature request related to a problem?

From a customer:

We use Customer.io for CRM and have the app connected to PostHog, but it only sends user profiles and events to Customer.io when new events happen

if there was an option to push historical data to Customer.io using the integration, that would be much welcomed

Describe the solution you'd like

Describe alternatives you've considered

Additional context

Internal ticket: https://posthoghelp.zendesk.com/agent/tickets/10203

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