With the help of our HubSpot professional services guru, we figured out how to do this. We setup a custom contact property where we set it to a value of 1 when a ticket is closed, then after a delay, we set it back to empty. The Custom Survey’s filter only sends the survey if that Contact Custom property has a value of 1, so the key is to time your Custom Survey to be sent while that value will be a 1. I also added in a trigger in my workflow to not set the value to 1 if that field has had a change within the last 14 days, this is how I don’t survey a contact more than once within a 14 day period. You can play with time periods as you see fit for your preferences. Here are screenshots of my Workflow and of my Custom Survey filter for reference:
