Is it possible to have separate tasks between PFM and Project Management in Project Plan?

Summary:

We have been using Project Foundation & Project Costing for several years, and just enabled Project Execution Management.

The users of Project Execution Management do not want to use the same tasks (expenditure types) that are used in Project Financials, they want to track timelines at a more granular level.

I believed I configured these granular tasks as Expense Project Enterprise Resources, and know that I did not select 'Create from expenditure type' when doing so.

When I viewed the project plan as a Project Manager, I saw all of the Project Financial Tasks.

Is there a setting to 'Decouple' the existing financial tasks from the 'Project Management' work area by default?