Whether to avoid collaborating with an academic because it would prevent them from being a reviewer on your post-doctoral research fellow application
To succeed in a competitive funding application such as this one, you will need to convince not only people who work in your field, but also those working in more distant areas. Therefore, relying on impressing a single professor who knows your work well is not sufficient. As @Roland comments, you are far better off improving the quality of your proposal through collaboration.