This is some BS
Garage Entry Door -

I didn't want to have to break open the walls (Remember, they're lath and plaster so they'd be a bitch to repair) so I measured to the next stud over and cut some blocks to tie the door framing to the house. This was my "test fit" of the striker side to make sure I cleared the electrical that was tucked into the wall cavity.

These were screwed to the trimmer with 3" screws and more 3" screws were "toenailed" through the next stud and into the blocks resulting in a couple small holes in the plaster that can be patched with some mud, sanded smooth and then paint touched up.

The hinge side needed much shorter blocks so I was able to screw those directly to the corner framing and then screw the trimmer to those blocks. Now I had to address the header..