Would patching the right side or converting to a double gang w/ wall plate be better?
No idea what the story behind this is. It's a single gang coax box, and just a hole next to it. Looks like previous owner started to patch the drywall by putting the backer in but gave up.
Converting to a double gang would be pretty tough with that stud there
Edit:
I didn’t realize that was just a backer board for filling it in. It would probably be easier than matching the texture, but only if you can put one in without damaging the existing drywall