What changes the decision?
A virtual copy, a related subset and a newly generated scenario are different results. List the systems involved, who may access sources, who operates the jobs and how failure is recovered. Procurement must name the product, edition, connectors and deployment. A banking use case is not proof of mainframe or message-format support.
What should your proof of concept show?
Use one controlled source snapshot or one explicit scenario. Verify required related rows, sensitive-field transformations, permissions and the exact business query. Test refresh or rerun, failure and cleanup. Measure storage, setup and operator effort with your workload.