This will affect timescales as it limits the dev teams ability to share assets and unable to submit the app on their own.
The client will be required to
Send: Distribution certificate (.p12)
Created Bundle ID: com.abc.client (have them ensure this was made "push enabled")
Send: Provisioning Profile (have them ensure this was created only after the bundle ID was confirmed to have been configured for push messaging)
Create using attached CSR and send: Production Push Certificate