I've just upgraded to 16.6, and I should have my review of the new version ready in a few days. I have just noticed something strange - I can't create a multi-model report in my workspace any more. It just doesn't appear in the list of model types.
Actually, it's not quite as simple as that - I can create a multi-model report in a project. Once, I've created one in the project, I'm able to create one in the workspace.
Weird .