its not necessarily too heavy of a clutch that causes it, ive seen this happen a couple times, hell ive never seen a clutch fork break until i broke one myself and cracked the sleeve of my throw out bearing. It all came down to because the tob and sleeve were not properly greased. Make sure you put plenty of grease on the sleeve and tob, cuz all it take is a small bind and its done for.
I personally have never snapped the lever before but i can guarantee its not the clutches fault, im sure it plays a part but with a properly greased tob and sleeve i can bet it wouldnt have happened. You will be surprised at how good the clutch will feel after you grease it too. Again i have an ACT extreeme pp with 6 puck disk (one of the hardest clutches out there) and have had no problems when its greased properly, hell i have yet to snap a clutch cable yet with this setup as well. Been 1 1/2 years too.
I thought i snapped the cable when the clutch fork broke, nope cable was in perfect shape still and its the original one