So I read the rules regarding USB Loaders such as Nintendont, and was curious if it would be allowed to burn the ISO file of the game onto a minidvd via an external drive.

Without knowing the exact setup that would accomplish this, I would say it's not allowed. Shadow is a game where changes in hardware can result in different loading times and framerate performance. So before allowing playing the game that way, we would want to test things out first to make sure there are no advantages.

Alternatively, we currently allow emulation and the like when playing ROM hacks of the game, i.e. Shadow Reloaded.