Got my hands on 2spd gearbox idler and drive gear and I must say that they are "a bit" stronger looking compared to the 3spd ones...
(2 speed gears at top, 3 speed at bottom)
I might convert the internals to 2spd just for the heck of it, if I break them again before Kershaw's transmission is here.
Also, I ordered a set of black RPM a-arms since I'm not really a fan of excessive aluminium parts.