Ok, the production version works without pre-created PDs, as you expected. I think what's happening is, for each instance, the code looks for a PD and uses it if found, otherwise it creates the instance with a scratch disk. In the v1 world, the scratch disk is no longer an option but I could introduce the following option: use PD if found, or auto-create one if not found. In that model, I'd be inclined to make the auto-delete setting hinge on whether we auto-created or not.

Alternatively, I could assume the pre-created PDs were more useful when we didn't have auto-create and I could simplify the code to always auto-create and auto-delete and not try to use existing PDs.  Thoughts?