Just finished the cam chain mod, but  feeling a litle concern about the risks if the chain breaks.
Total engine failure i guess, but will it bring the engine to a complete stop or just shut down? Just thinking, if it is a risk. Consider you driving a long fast curve and it breaks down.

This question may be along the lines of what if the connecting rod breaks or what if the cylinder head cracks in half. If cam chain break often or any of these other issues happen with regukarity then the question becomes why ride motorcycles at all.

These chains stretch, which is the source of the need for the modified tensioner, but should not break until way past their serviceable(useful) life. The tensioner mod is a very economical safety item that allows you some time to replace a chain that evolves into an unserviceable state. I imagine if you drive the engine to the point that the chain breaks then no piece of equipment will protect the engine.

I think the cause of your question is derived from the knowledge that there is a weak link in the engine, the cam chain tensioner, and you logically ask the question what else is defective or suffers from faulty design. I, personally, am very confident that if or when I am approaching a catastrophic failure that the proactive steps I have taken will allow me plenty of time to take the appropriate corrective action.

Hope this alleviates some concern.