Symptoms
Client need to be able to determine if there are any running instances of a workflow (against a SPECIFIC version), they need to make a database change but can only perform the operation once older versions of active workflow instances have been flushed through the system.
Diagnoses
The ExecutingProcID will be the version the instance is running on (Version shown in Workspace.
The status will show 1 for running instances and 2 for active (as per ServerLog.Status).
There is also a start date column which you can use in a query.
Resolution
Client was able to build a script to identify the versions.