I'm thinking there is, of course, such a thing as a two-sided, through-wall outlet box. Because 2x4's and drywall are standardized enough so you can make a box that will work for this application -right?
I do some web-searching and come across some post in some DYI forum from 10+ years ago where someone is asking the same question, and no, for some reason there is no such box.
I also come across this:
Seems to be a video made by someone who patented a through-wall double-sided box. Really? A patent for the obvious?
It's crazy that these don't exist.