Hello Jared,
Admin frameworks are something that we’ve largely struggled with. Upcase and Exercises are great examples. Upcase uses Rails Admin with no test coverage for the provided functionality. Unfortunately we’ve had failures and regressions due to this.
The exercises app on the other hand uses custom admin pages with test coverage: https://github.com/thoughtbot/upcase-exercises/tree/master/app/controllers/admin. I have more faith in this admin, but it is obviously more effort to maintain and does not have all the functionality we would get from an configuration driven admin framework.
The most recent Weekly Iteration on the Flashcards feature contains a discussion of our choice to implement a custom admin for Flashcards in the Upcase repo despite having Rails Admin available.