Here's the thing. You can't just hold down the 'B' button and expect it to turbo the 'B' button. It's not the way a modded controller works. If you physically hold down the 'B' button, it overrides anything the mod chip is trying to do. So even if the mod chip is turbo'ing the B button as fast as it can, if you are holding down the B button, it cancels it out.
Which is why I say it's easier to implement on Duo - I just program the controller so that when you hit, say, the left tactile switch, the mod chip starts turbo'ing the B button (and since you're not already holding down B button, you should win the battle
)
On sleeper, not sure how to implement the same thing without using another button that's already being used in-game.