FCCS delete method in groovy script returns error

We have a requirement to delete members in Accounts dimension via a groovy script. However the delete() method returns an error stating it is not allowed. We've been able to do this in Planning and Budgeting successfully but it apparently is not allowed in FCCS.

Has anyone been able to do something similar in FCCS?

In FCCS the script throws the following error when validating/compiling:

Error:The Groovy script failed to compile with internal error: Compile Error:
oracle.epm.api.model.Member#delete() is not allowed Rule JFI_FCCS.Consol.JNL_Delete_Shared_Members'

Here are the script lines that work successfully in Planning and Budgeting but fail for FCCS: