As a pokerplayer i find this conversation really interesting. Not much comes out of the highstakeworld online  but i can gve some information. In both )texas holdem and pot limit omaha the topplayers use alot of tools to study and play  GTO. However its not humanly possible to play GTO you can spend 100s of hours for spots that if you play professionally never will occur during your lifetime. Therefore topplayers focus hard to study the low hanging fruit commonly occuring situtaions. As i said all toppplayers study GTO but the player i think is the best is Berri Sweet whos playing superexploitive. For sure he knows and studies GTO but his playstyle is exploit