It's not possible right now. You can only run full games dumps published on e-shop, but not aditional content or apply patches (currently, e-shop is unavaiable for gateway, maybe it will work on next gateway update).

um you can run game patches on roms, i have downloaded pokemon x y mario kart updates prior on 7.1 and the roms read the update data just fine i would think they would also be able to run dlc, however due to the 7.0 encryption gateway cant read youtube nor settings, the eshop i think still works unless that got encrypted as well
