Yep, was discussed about 7-8 months ago.
Short version, original design of the hammer spring tension adjustment was similar to FX. Not identical, but the claim was that they were similar enough that FX made something if it. And because of that, BRK upgraded to a better design, rather than fight a legal battle.
I'vs used both designs. They both accomplish the goal of incrementally and repeatably adjusting the hammer tension, but the current/upgraded design feels a bit smoother, and offers an additional fixing bolt. Ie, upgraded wheel design is smoother and holds the rear subframe to the rest of the gun more securely.
Other than the additional bolt, the main difference was that the original design was a sort of corkscrewed ramp (think threads on a screw) while the current one is a worm drive. (Potato puhtahto, but such it is when lawyers get involved).
(Working through some mental images, the newer wheel might have more rear hammer spring support than the OG, as in a longer rear guide, but don't hold me to that, it's been months since I've been in that part of the gun).