Question: tvhm when to do dlc?
Answer: Do the DLC in Normal before you wrap up Normal, then start TVHM and immediately do Tourge's Campaign of Carnage. The complete the rest of the game while farming Badassasaurus and doing the Bar Brawl fights. Then do Tiny Tina's Assault on Dragon Keep at the end of TVHM and progress until you can get a Grog Nozzle.