Reports - On Hold data needed for Phone Call conversations

We use the metric Hold Time for agent bonuses, and we were informed via Fin that it isn’t available in the UI nor is it available via API (I’ve tried searching for a method to calculate it using this Conversation Endpoint and it wasn’t very clear what conversation_parts we can use to calculate).

Would love to be able to have this data readily available; we don’t want our agents putting our customers on hold for long periods of times, and we don’t have an easy way to measure this.