This is why we manage acquisitions and due diligence in house. There seems to be too much inefficiency caused by allowing outside teams to run due diligence. That said, I think that regular debriefs from the external team on what they are finding, red flags and issues to be addressed would be helpful. This could be done by starting the integration team meetings prior to close and including both the internal and external teams in those meetings. In addition, a standard checklist or playbook for integration that includes line items for knowledge transfer and specifics around what they should look like could be helpful.