Interesting.
I googled hood latches and saw kits with 2 long and 1 short metal threaded screw for each latch all with nuts.
The remains I found of an intact and probably original wood block had one short wood screw only, no nut.
We in OZ did not get your metal subframe, Ours are all wood .
I wonder if we made our own wooden blocks here and used these wood screws instead of nutted screws ?
After all, the third hole was only to hold the latch and wood block to the shelf, so the assembler on the assembly line could place the whole package onto to the chassis without fiddling to line up holes.