I would highly recommend you to please post this idea at our ideas forum (here).
Our product team, who monitors the forum regularly, can read your specific use case and understand why this would be a useful functionality or change. It also helps other customers facing the same issue to advocate for its implementation on your behalf by upvoting on the thread as well.
It’s 2025 and we still don’t have this capability? I think HS is purposefully omitting this feature because it ultimately can impact their credibility -- e.g. if someone abuses this feature (which could be easily done), it could continue to ripple -- I wonder what other platforms feel about this, etc.
It is crazy that under Marketing Enterprise/Hub, you can’t simply click “resend to unopened contacts” as an action shortcut. I wish HubSpot would actually resolve this vs. responding back with "reach technical support to assist with our elongated approach to an otherwise simple task.