Add hourly frequency limits for proactive Messenger workflows

I need to limit how often a proactive Messenger workflow appears without suppressing it for a full day.
The current frequency options are days, weeks, and months, or sending every time.
Please add an hours-based limit, such as once every 3 hours, or a configurable cap on sends per hour or day.

This would let us offer help again when a customer retries a failed payment later the same day without showing the message on every attempt.