I’m from the HubSpot Product team. We’re looking at adding custom objects to the Zapier integration. 
Can you help answer a few questions so we can build the right functionality?
1. Do you need Triggers, Actions or both?
2. What’s your use case? e.g. I need to know when a new custom object is created in HubSpot, so I can create a new record in Airtable.
3. Can I reach out to you to learn more?
Reply directly in this thread or send me a DM. Thanks!