I recently racked a 9U network rack, with four mounting holes. The right side were all done with 5/16 inch lag screws (top + bottom right). I then used those flip toggles to get the left side since it was abnormal stud spacing. I am running a UPS (30 lb), a 10 lb udm pro, a 10lb switch, 45 lb network rack. I tried putting my weight on it and it’ didn’t move. I think it’s 1/2 inch drywall. Curious if thats enough to hold up the rack without worrying about stuff falling
Yeah, I would do the plywood. I know from (work) experience that things may appear solid, but over time the drywall can fatigue. You could even run some boards across the stud spacing and then bolt your rack from that. You could perhaps run a board across the wall under the rack to bolster it there (screw into studs, preferably)