KZ400 New Brembo brake pads

I bought a set of new Brembo pads for my KZ, not because the old ones were worn, but for improve braking performance. I'm also going to take this opportunity to regrind the disc (remove the small grooves).
When I received them, I checked that the dimensions matched in every way:
 

But the brake pad on the non-moving side has that kind of nipple:
 

I was going to file to remove it, but now I don't know if it's some kind of improvement and it's better to leave it like that
 

Has anyone else happened this or know anything about it?

I'm not familiar with your bike, but caliper pistons are typically cup shaped, so that raised bump on the back of the brake pads will just fit inside.  

That said, Kawasaki did use some caliper pistons, on some models, with an insert inside the cup, so that raised bump wouldn't sit flat with pistons like those.  

The pad for the "fixed" side on CMNSL also shows the raised centre ? (possibly to allow for some degree of articulation)



 

I asked a friend, and he told me that's indeed the case. The originals had already introduced that modification at some point.

Thanks again, everyone. I'll post the results of the new braking update.