4% is accurate from what Riku had before he lost his work, now he's starting over, but I'd half that percentage since I still have to go over the script to edit and localize it and make sure it's ready for the game, and that's just the first pass, it's going to take a lot of testing and script revising before this is finished, and that's without touching the graphics.
The game will be patched through my own patching format and patcher, but it'll still use ndstool to pack the files, it'll a one click process to produce the patched rom, which should make it easier for everyone.