My $0.02.
I think you will find there is a small pocket behind the top left bolt with hole.
The residual oil in the valley will be right up to the hole in the bolt, any additional oil will cause oil to flow out the hole in the 2 top bolts.
Those 2 top bolts are what? 3/8 of an inch below those 2 huge 1 inch holes from the valley into the timing cover.
It takes a very small amount of oil puking down from the heads/rockers to bring the valley oil level up to those huge holes, never mind any splash from the vehicles motions.
Lack of oil usually results in heat, as in blue rockers or rocker balls/shafts.
Never seen blue, wear, stretch, - no heat on the timing chain, or gear.
As to the hole in the thrust plate, that I broke several drill bits trying, never made a hole.
Look at the broken thrust plate in the pix.
It fractured, it didn't bend, or distort, it broke like the cast iron sprocket, cuz it's case hardened or ? - hard, so drill away.
I always use the 4 bolts, one with hole in proper location, no lock-tite.
Good luck,