Some tech I've been testing with:
1.
Leovold, Emissary of Trest slots nicely into the sideboard. 1-2 copies are worth running to mess with decks that rely on cantrips or drawing a ton of cards. But even against a deck like D&T he's pretty good since he can help mitigate StP and Rishadan Port. I am undecided if he should actually take the mainboard slots currently occupied by TNN and send TNN to the board -- since generally Leo is better against more random matchups, especially combo... but on the other hand, TNN is amazing at getting in there for the last couple points of damage. Perhaps a 1/1 split? With DRS, it's not usually too difficult to meet the color requirements of casting him, and against any deck without Wasteland you can fairly safely fetch out your lone Tropical Island as needed.
Note that I also like to run Kolaghan's Command in this deck -- 1-2 copies somewhere in the 75 really helps give you the edge against other Delver decks. These cards push the deck towards playing a little bit more like 4C Control in the mid-game, except you're playing a more focused and aggressive early tempo game.
2.
Bitterblossom -- mainly considered for the comeback of Miracles. This makes it so that they have a difficult time answering all of your threats, and if it goes completely unanswered for awhile, the damage from the tokens quickly escalates. It's also not too bad against other creature and midrange decks, as providing chump blockers and some evasive attackers can help win in a stalled ground state. Might also be worth bringing in against Turbo Depths, as having blockers for Marit Lage can buy you some time to find Diabolic Edict.