Thanks so much for the kind words! I LOVE the Joker idea and hope to include it in one of my own games soon. We'll be running a game jam for BFB modifications and expansions soon, so I'd strongly urge you to consider typing it up when the time comes! And while I'm thrilled that you've enjoyed playing the game, the fact that it's sparking bits of game design in your own mind is the highest praise possible!
As promised, the #BFBJAM is now LIVE as is an SRD for the game! If interested, I'd strongly encourage you to type up your rules modification and submit it as a rules supplement for folks to use! https://itch.io/jam/bfb-jam