Not sure if you got your answer, but no, they don't seem to. If it's a code that only needs to be enabled once, you could just load up the original ISO, verify it's working, save, then switch back to the Undub.
I'm trying to edit Robin's eye textures. I injected the edited texture, saved it with DXT1 (the only format that worked properly after injecting) and dumped it to check. It looked fine, but in-game, it's a bit glitched.
Any idea what went wrong?