if you are a professional editor, is is YOUR JOB to do tests with the media from an Arri Alexa, or any camera, before you start the job. You don’t wait until the footage shows up to see if it will work. If you have problems, you will look like a fool to your client.
The Arri Alexa will record in ProRes4444, but you MUST communicate with the client and the DIT on the job, to discuss how the job will be shot, and what resolution will be chosen on the camera, when it is set up. If you say “it is not my job to contact the people who use the camera” – well, YES IT IS YOUR JOB. You are part of the team, and they must respect you – the editor, and discuss with you what they are doing.