I'd like to propose a theory on the probable use of those thingys on the upper tip of the kampilan's blade.
I'm not aware if this had been proposed before,
but my theory is that those things are used to deliver poison to the enemy during combat.
My train of thought would be:
[1] Visayans customarily applied poison on their kampilans & krisses [WH Scott, in Barangay];
[2] In the Battle of Mactan, it doesn't come as a surprise thus that Pigafetta reported the use of poison arrows by the natives against the Spaniards;
[3] After Magellan's defeat, Magellan's first native ally, Rajah Humabon, in disappointment over Magellan's failure to defeat Humabon's enemy [Lapu-lapu], reportedly ordered the extermination of the surviving Spaniards via poisoning;
thus once again, chemical warfare really looks like a typical method of defeating the enemy;
[4] The kris being wavy would have a longer total blade length compared to a straight blade of the same overall length -- as such when the kris was laced with poison, more poison can be lodged on the blade as compared to a straight blade; the point is that the kris' wavy blade then becomes an ideal weapon to deliver poison to the enemy;
[5] Now for the kampilan which Scott said was also laced with poison, being a very long sword perhaps it made sense to just concentrate the poison on the blade's tip;
[6] Now on how to operationalize the idea, I thought that those many perforations and jagged edges would make an ideal repository for the poison (normally the sap of a certain tree, per Krieger, when Krieger described how the Luzon tribes source their poison);
the spikelets and other protrusions on the other hand will provide good platform for injecting the poison into the flesh of the enemy.
On how to prove or debunk the theory, these are the things that can be done --
[a] if Pigafetta had a post-battle account, we should find out whether those wounded by the "large cutlass, which looked like a scimitar" were noted as having experienced symptoms of poisoning (e.g., nausea, vomitting, etc.);
[b] it should also be established whether the Visayans' kampilans had those spikelets and perforations in the first place;
[c] for those in the US and Europe who have access to crime laboratories, those spikelets and perforations on the kampilan should be swabbed and the sample taken for analysis of traces of poison, a la CSI 
now if you have etched your kampilan and obliterated any chemical trace on the blade's tip, shame on you! 
[d] given that kampilan must have been first developed in Borneo, and then it went up to Mindanao first before reaching the Visayas and then Luzon, it will help if we can find out whether those original users of the kampilan laced their blades with poison also.
Back to the subject on whether in the first place the Visayans had kampilans similar to the ones used by the Moros of Mindanao (i.e., with spikelets and perforations), I think that's the case.
Because Pigafetta described the fighting style of the men of Lapu-lapu as -- "When our muskets were discharged, the natives would never stand still, but leaped hither and thither, covering themselves with their shields."
Now earlier, the Europeans and later the Americans described the Moro fighting style as exactly like that. So if the movements were the same, it stands to reason that the weapons used must have been very similar if not the same.
Admittedly, all of the above are highly speculative.
But hey, to echo Vandoo, let me end by saying that "That's my story, and I'm sticking to it!"
Attached are pics of various spiked tips, as collated randomly from pics in the forum.