Quote from Mask_of_Death
Perhaps there can also be an option to create your own too. However, instead of making all new dimensions, perhaps there can just be command blocks to TP you to the different desktop themes in the same dimension. It wouldn't have to use heavy-duty redstone, just a button and command block.
EDIT: Also, perhaps the different doors in the different desktops will be linked to different TARDIS exterior models, and leaving it will change the default TARDIS model to whatever its should be. So, there would only be one TARDIS (and TARDIS item) ingame.
Sounds good. The one dimension thing kinda slipped my mind to be honest, since the current console rooms are in the same.