Take the sample below. the Custom SRA Layout is already selected as the default and the Seeded layout is already Inactive:
However, the seeded layout can still be selected when we go into Payments > Task List > Send Separate Remittance Advise:
To suppress this, go into Setup and Maintenance > Task List > Search and key in "Manage Formats" and search for "Disbursement Separate Remittance Advise Formats":
Open the seeded layout and end-date it:
This will effectively suppress the layout from being selected from the SRA screen: