we discussed it, and thought it would be even easier to just copy /code/ and /content/ folders as is directly into the <AnyGameName> path.
no need to rename the RPX to ID4.rpx anymore.
go to "sd/wiiu/games/" and create a new folder here with your game name and copy "code" and "content" folder.
go to "sd/wiiu/saves/" (we changed the save folder name) and create the same folder name than your game here. no need to create "c" and "u" inside it.
no need to create the save folder at all, it's all done by the game !
Done !
I wouldn't make the folder of the content files too long, otherwise you could run into problems when a game has many sub-folders and long paths. FAT32 (and also the FSOpenDir function of the WiiU) only accept paths up to a certain length. So if a game has a lot of folders it could be possible that you can't place all the files on the SD because of the maximal path length. I don't know if there are games that have such long paths but it could at least be possible.
That could also be the reason why golden45 placed the contents on the root of the SD.