I would like to side-mount this double gang box as shown to install two switches. My concern is that the 1/4” holes in the back of the box will be a code violation. I have looked at other 2 gang metal boxes but all seem to have these large holes in the back, presumably for mounting the back of the box to concrete.
BTW I’m planning to run the conduit up from the left knockout so I can a attach it to the stud with a support bracket. I believe support is required within 3’ of a box for EMT, although I see some conduits in my basement that are only supported high above the box where they contact the ceiling joist.