The problem with most of those cheats isnt that they couldnt be ported over, its that its not practical in the slightest. These cheats existed because there was no practical way to mod cartridges back in 1996. We have access to that data now, it would be a million times easier to just mod the game files than to recreate these cheats.
As for the Koopa shell cheat I am a little doubtful that it would even be possible. The cheat makes a specific note that you have to apply the cheat before the title screen is loaded which is not possible with this unofficial port.