Currently, the subject line for follow-up steps (e.g., Step 2 onwards) in a campaign is locked and cannot be edited. This is intentional to keep emails threaded under the same subject line. However, users have requested the ability to customize subject lines for follow-up steps while still maintaining flexibility in their outreach. This would allow more tailored messaging per step without losing control over campaign performance and personalization. Request is to explore an option where users can edit subject lines per step while optionally keeping threading behavior intact or configurable.