The program players currently in game have opted to keep their characters programs—with all the abilities, functions, and dissolving into data this entails. That said, the question above about apping AIs does also apply to this case; if a player wanted to humanize or otherwise adapt a digital character to a more physically normal body, they could request this in the app. (On a personal level, this mod encourages you to reach out if you have questions—I play Rinzler!)

Players are welcome to elaborate their characters with headcanon (fanfic-derived or otherwise) where it does not conflict with the canon story/abilities. That said, they would need to have a higher ratio of canon to noncanon in order to be appable as a canon character. Player-created AUs are not allowed at this time, so if the fanfic altered your character's history enough to make them an alternate version, we would not be able to accept the app.

Last, there is absolutely a test drive! As per our calendar, the next one should be coming out this Friday. If you're interested in being alerted when it comes out, we suggest following our mod plurk.