Thank you everyone for your patience, I can share an update. The good news is we have kicked off engineering on a foundational project that will support many future enhancements to our SLA capabilities. Once we complete this first phase we'll start work on adding new features, expected sometime in Q4.

In the meantime, we have new documentation on how you can measure internal workflows using child tickets and SLAs. https://support.zendesk.com/hc/en-us/articles/4404111727514-Defining-OLA-policies-using-internal-SLAs-and-child-ticket-side-conversations

While this does require a child ticket for each step, we do also plan to support reassignment workflows too. This is where a ticket is reassigned to one or more groups and each step has its own internal SLA, as well as the overarching customer-facing SLA. This is something we'll be working on too and I'll share progress when I can.