People make up elaborate backstories for the fun of it, not because they expect the game to acknowledge it.
I find that rather pointless for this game. At an actual D&D table sure, your DM might decide to roll with the backstories of the players so that could evolve in interesting adventures. But I wouldn't do it for a videogame where such things don't matter to the game. Plus there is a chance that the custom character also has a pre-determined backstory yet to be revealed in some plot-twist.
