Managed to remember the TGK 231's. Correct me if I'm wrong but I think Djokovic would be using the TGK 231.1, Microgel Radical MP mold in flexy form, around 60 flex, tight pattern?
The 231.2 is also tight pattern but is stiffer, more like a pt57e in flex. Was used by Chardy and Casey Dellacqua. Has much more pop but feels quite different to the 231.1, a little like the difference between a pt57a and a pt57e? Plays a bit like an uncapped pt57e in my opinion, quite liked it.
The 231.3 is the open pattern flexy version used by Cilic. Could be same layup as the 231.1 but in 16 19, so around the 60 flex mark?