I'm learning GTO, and don't have much experience on live games. Just to share some thoughts:
I think GTO theory is always correct, and applies to any situation. But that does not mean that a specific solution is correct for a specific game.
In live games where the strategies vastly different from a GTO player, the solutions in GTO wizard simply does not apply, not only because that you need to exploit to deviate from GTO, but also because the input (such as bet size, effective stack size, etc.). If you have a GTO solver that can run preflop, input the parameters that are close to a live game, then the preflop range will be very different than GTO ranges. I believe such ranges are still good guidelines.
As already been pointed out that live games generate way more multi-way pots. But that's a weakness of existing solvers. And the amount of computation would be huge (similar to the solution of three-body
if there is such a solver. Seems GTO wizard has access to super computers, not sure if it has such solutions.
For big stack games, GTO postflop is still good, just need to adjust up value-bluff ratio against multiple players, I think.
Just my 2c...