I see that "to acquire a new Badass Token, each Badass Token will require a greater number of Badass Ranks than the previous one. However, there is no limit to the number of Badass Ranks and Tokens that can be earned."
However, what happens once all challenges are completed (5/5 resp 1/1)? Apparently the challenge is just grayed out and does not indicate any further progress, so it seems like there is an upper limit to the number of tokens.
Do I possibly silently acquire more tokens even after 'officially finishing' a challenge?