I still think that greneng is just an empu's signature and has nothing significant in its physical function aspect. However, I must say I agree with the notch in a khukuri theory - being blood flow stopper.
Another thing to note, though both types of weapons came from Hinduistic culture, empus were very revered that sometimes even the kings married off their daughters in rewarding their efforts. The same could not & cannot be said about the kami caste (khukuri makers) - They were considered untouchables
