The actual queries are written in the vizqlserver logs.
The location and structure of log files are mentioned in the help:
Windows: C:\ProgramData\Tableau\Tableau Server\data\tabsvc\logs\vizqlserver\
If you'd like to track several dashboards only,
the Performance Recording on the server could help:
Thanks for the suggestion. This seems like a good option.
I still contend that the scheduled query syntax is saved SOMEWHERE in the Workgroup database. (or some other yet to be identified schema)