Quote Originally Posted by FritoBandito View Post
As of patch 2.2, the following trials and raids will count toward achievements requiring the completion of high-level duties with a full party: The Howling Eye (Extreme) / The Navel (Extreme) / The Bowl of Embers (Extreme) / The Whorl Eater (Extreme) / Thornmarch (Extreme) / The Binding Coil of Bahamut (excluding Turn 3) / The Second Coil of Bahamut
You answered your own question. The only instances that will count towards the achievements is Extreme Primals and Binding Coil (excluding Turn 3). No dungeons outside of story dungeons (Prae and Cape Westwind) allow for 8 people to make a Full Party.