Hi Ming,
Absolutely, this is something we'll be reviewing in upcoming releases, how to share this schema and also support the evolution of it as you deploy new versions of the processes. Meanwhile, we'll be focusing to enable the Data Index to work independently from the protobuf, meaning that only what we call technical entities ( ProcessInstances, UserTaskInstances, Jobs ) would be available to query.
That means that querying domain specific entities wouldnt be avaible as a side effect. Would that impact your use case at all?
Thanks