I’m a guy who likes to make guesses. So I’mma guess:
Any yoyos sold within the U.S. featuring a non-Dif-e-Yo KonKave bearing (truly curved across the bearing’s profile) would be affected by Dif’s patent. In other words, you can’t include Chinese-made generic KK’s without a license from Dif.
However, Center Traks or even Center Trak-alikes are not subject to that patent. The flat area in the profile makes them different enough. You can include these.
I’m guessing YYO was being on the safe side, but then discovered that since they’re using CT-type bearings rather than KK-like bearings, they were fine all along and will now be including them.
Do I win? Do I win? 