I have found a few more articles to share with you:
This first webpage outlines the Canadian transport measures and guidelines for air travel. Although not necessarily applicable to all aeromedical evacuation companies, some might find these resources useful for repatriation flights on airlines or for personal travel.
This second site is Guidance for first responders who expect to be in close contact with suspected or confirmed COVID 19 patients. The cleaning guidelines are more applicable to land transport vehicles, but there are some excellent triage and patient assessment questions to help properly prepare for personnel protection and safe patient transport.
https://www.cdc.gov/coronavirus/2019-ncov/hcp/guidance-for-ems.html