Tracking Post Sales Demo Follow-Up Emails in HubSpot

Hey, has anyone ever tracked Post Sales Demo Follow-Up emails sent out percentage or numbers in HubSpot? I've built an automation that uses demo transcript and builds a potential draft under the Deal which would make it easier for the Reps to send out emails but I'm struggling a bit trying to find a proper metric to track it. Ideally, would not like create custom property as it would mean, there is no historical data to be compared but if no other option exists, then that would work as well. Much appreciated and thank you for your thoughts! 🙏