Cylinder Heads: Lash Adjuster - Bores

Truck info:
2009 Ford F-150 XLT, Supercab - 4x4
Modular V-8 / 5.4L (330 Cu In) 3v Triton (FLEX)
Milage: 160K (Miles)

I removed the camshafts to inspect them while updating the timing system components. While the camshafts were removed thought it may prove useful to inspect other head components too. When the lash adjusters were removed I inspected the bore holes that house them. At the bottom of the lash adjuster bore is another hole, (Not the oil feed hole midway down the bore), looks out of place.

Each of the 12 bores on both the Lt/Rt heads have these holes within them.
The hole size, shape, and locations are all different from one another. Which I also thought was weird. These holes look as thou the metal was eaten away or was punched out some how?

I found no indications of metal or other debrie from with in the head itself. I also used low pressure air to try an clear any potential debrie from the oil passages. The compressed air didn't dislodge anything and the air seemed to flow unabstructed.

When draining the engine oil, I didn't observe any metal debrie within it nor the filter. After fining the holes in the bores I removed the oil pan just in case. Here again found nothing that would sound the alarm bells.

Need advice as to wether this is normal (OR) not for these types of engine heads?
This is the first Ford 5.4L 3v cylinder head that I've had to deal with and have no frame of reference to defer to.

At this point I'm not sure if this is normal for these heads? Don't want to invest the time, effort, and money into something thats damaged beyond repair.