(Tejahn) Question Thread

Is it possible to change the battlefield to a custom image? And if so, what is the best way to do it? I opened both the TRANSITION_BACKGROUND and TRANSITION_BACKGROUND_2HG in a Hex Editor and noticed that they say DXT1. All images I usually deal with say DXT5. Even when I save the image as DXT1 it still doesn't appear in game. I've attached the TDX files in a zip so anyone can have a look.
EDIT: Even after deleting the above-mentioned file from the unpacked and repacked DATA_CORE the game still generates those images for the battlefield. I also unpacked DATA_DECKS_D14, DATA_DECKS_E14, DATA_DLC_0001, DATA_DLC_0002, DATA_DLC_0003, DATA_DLC_004, DATA_DECKS_F14_PACK1, DATA_DECKS_F14_PACK2, DATA_DECKS_F14_PACK3 and didn't see TRANSITION_BACKGROUND and TRANSITION_BACKGROUND_2HG in any of the folders. This is some kind of spooky science or it's as if they're just appearing by magic.