Group Admins cannot upvote or comment on Idea Exchange. It's the same license cost, and we use Group Admins for different Portfolios so all of our admins aren't seeing everyone's templates, projects, etc. BUT we all contribute to the success of Workfront within our organization and would LOVE for ALL of our Group Admins to be able to contribute (not just follow) Idea Exchange Ideas and therefore have an effect on the popularity and necessity of an idea.