Form Security for connected EPM instances

Summary:

I have two EPM instances: A and B in this context. EPM A is the primary Planning instance and EPM B is a supplemental Planning instance where we perform budget allocations. I have a form with allocation rates in EPM B that users want to view in EPM A. I can add the form to the nav flow and view it in EPM A without issue.

When the connection from EPM A to EPM B is established, I use service admin login credentials. (no issue in connecting the instances)

When a user, a Planner, views the form in EPM A, does EPM B use the user's credentials or the service admin that established the connection?