Disabling CreoView and visualization for Project contexts

We recently implemented ProjectLink for external supplier collaboration. There are things we can share and there are things we cannot... Is there a way to turn off CreoView, thumbnails or secondary content in Project through policy administration or some other means? I'm finding that if a representation is created and then the file is shared, it's shared even for files that I don't want shared (and don't share). In other words, my suppliers can see more than I'd like. 

Has anyone else run into this? How have you solved it?