I'm shocked that this idea isn't already listed because a number of people have already discussed being disappointed that it isn't currently supported by TeamViewer.
It would be a useful feature if TeamViewer could be set to record an *incoming* session.
Our use case (and that of a number of others in the Community forum) is to monitor/review works done by other parties on our equipment.
This seems so fundamental from a safety/security point of view that I don't know why it hasn't already been implemented.
Edit: So I have found 1 post that claims that this feature was added in TV13 but even that poster said he couldn't find any documenation for how to use it.