Thanks, again, for your reply.
The thing is, I think 123ab spoofed the version numbers with the highest possible value, so that they wouldn't update no matter what.
If that's the case, a regular fw update via the 3DS built-in feature wouldn't work / update them properly.
Downgrading to 9.2 would restore the sys modules to unhacked modules, but all the other, newer modules (that didn't exist on 9.2) would stay installed and possibly hacked, I'm worried about that too
Have you tried your method on your system, or do you know someone who did?