You won't harm it at all with the twilight hack,
and the Iso loader only works with console's with a modchip and firmware 3.2 or LOWER. 3.3 took away the ability to use trucha signed disc unless you run them through homebrew regionfree.
So as far as i know, and i did a heap of homebrew.. there's absolutely no way to load it on a console without a modchip other than the TP hack.