The new replace order feature allows users to update an existing open order in one step through the `/v2/orders` API, replacing attributes such as `qty`, `time_in_force`, and limit price. This feature reduces buying power during the replacement process, which can be calculated based on the larger of the two orders being replaced or placed. Users can now configure options like trade confirm emails, suspend trading, and no shorting through the API, with settings documented in detail. Alpaca has an invite-only Zapier integration available for testing, supporting 2 triggers and 6 actions, and is working on a public roadmap to communicate upcoming features and gather user input.