I have a very old house that at some point many decades ago had its electrical system partially updated (mixed knob and tube in a 70s 200A panel). Part of this upgrade relocated the panel to an interior wall around 3 feet from the meter. There is currently a 2" conduit connecting the meter to the load center, and the load center is surface mounted.
I would like to re-route the entrance wire so it penetrates into the interior wall, then flush mount the load center. I'm working with very limited space (2x4 walls, not enough room to fir it out to at least 2x6), and don't think it would be a good idea to run a large conduit through the wall cavity.
With that in mind, I'd like to just run a single SEU cable of appropriate size between the meter and load center horizontally in that 2x4 wall, with just nail plates protecting it. Is this allowed per the latest NEC?