Final answer:
Documenting assumptions and choices is a critical step in finalizing internal and external ethics policies before approval, providing a transparent basis for the policies.
Step-by-step explanation:
The important action needed for the finalization of internal and external ethics policies before approval is documenting the assumptions and choices made in the drafting of the policies. This documentation is crucial for ensuring transparency and for later review and understanding of the policy foundations. It is not necessarily to have policies identical to peer organizations nor to test the policy in a deployed setting before finalization.
Also, discarding open issues would not be advisable as they should be resolved or noted for future consideration. The policy process, which includes agenda setting, policy enactment, policy implementation, and evaluation, emphasizes the importance of rigorous development and assessment of policies to ensure they are effective and ethical.