Savchenko-SZolkowy are doing throw triple axel (although I don't know if they landed one clean in a competition). Other than Inoue & Baldwin in the past, I don't believe anyone has landed this.
AFAIK Kawaguchi-Smirnov still have the throw quad salchow on their list. Is anyone else doing/attempting this? (The Zhangs had landed it LONG ago in a competition, but not at senior worlds, AFAIK). With the COP there is less incentive to try this very dangerous throw.
I think a couple of pairs are doing throw triple lutzes. Correct me if I am wrong- Denney-Coughlin? and Duhamel & Radford?
Only a handful of pairs are doing even throw triple flip. In the past it was S&S (I think they are still doing this) and Obertas & Slavnov (also Obertas & Sokolov).
Throw triple toe is actually a difficult throw but it has lower value, so I don't think anyone is doing this. They would rather do a throw 3sal or 3Loop. Petrova-Tikhonov used to do this (also Shishkova-Naumov) but they replaced it with throw 3loop to increase the difficulty. IMO the 3t is more difficult than 3S and 3R when it comes to a throw.
May be some junior pairs are working on more difficult throws, or are they mainly working on difficult entrances? I would like to know.