Removing a vendor's ACH Payment details without deleting their records is a great idea, @grosslf. However, this function is currently unavailable.
The applicable options we have, even though one of them isn't a choice on your end, are to update the Bill Pay ACH information once they changed, or make your vendor inactive and create a new profile. Yet, this will affect their records.
Let me know if you have further questions about managing your vendor's payment information by leaving a comment below.