Looks like the picture in first post is of something slightly bigger than our stuff. That makes it a completely differend story as with small 2-strokes.
In our use, where stability is everything, I would try to avoid any bigger cutouts to improve lubrication/cooling of piston like Randy suggested. That is especially so in ringless ABC's or AAC's.
Seeing lubrication holes for wristpin smells like an attempt to improve something when the problem is actually elsewhere, like in bad materials.
In my case, I use 100% piston scavenging, that's the reason for those big cutouts. But then, I rely on the ring in sealing stability. Even though materials are right, I doubt it would work well without the ring.
L