LG 4922W5A057G dimensions
I purchased an open-box LG microwave oven which did not include the upper or wall mounting templates. It seemed silly to spend $20 for a piece of paper, so thanks to a YouTube video I found of someone else installing theirs, I was able to extract the necessary measurements.
Holes J and K for the bolts to attach the microwave to the bottom of the cabinet over it are 10⅜" from the back wall. J (left side) is 11⅞" from the centerline; K (right side) is 13 7/16" from the centerline. Both of these holes should be ⅜" (technically the bolts you use are ¼", so depending on how good your tolerances are, you might be able to get away with a ¼" hole).
The power supply hole (M) is 5⅛" from the wall and 6⅛" from the centerline. It is 2" in diameter. In my experience, the wall distance was closer to 5½" and a 1 3/16" hole was more than sufficient (I had a hole saw in that size already and used it).
The roof vent opening (L) is 6½" on either side of the centerline and 4½" for a recessed cabinet (at least ¾" recess) or 5¾" for a flush cabinet.
The wall vent opening (F) is ¼" below the bottom of the cabinet and has dimensions of 4" tall and 12" wide, 6" on either side of the centerline. The centerline should go through the ▽ symbol on the bottom mounting bracket.
Hope this helps someone!