That is good to hear that the BDS is slightly thicker around 0.2mm thicker or about 8 to 10% thicker on average.Its a bit hard to measure but the BDS axle is slight thicker.
The stock axle on the sprocket side measures at about 2.69mm thick and the BDS is 2,89mm.
On the brake disc side its about 1.62mm vs 1.83mm
I imagine they make it thicker both on the inner diameter and outer diameter so the stock stand pin still can be inserted into the axle while the wheel hub can also still go in the axle easily.
Thanks HKMP7