Text trained LLM's are likely not a good solution for optimal play, just as in chess the position changes too much, there's too much exploration, and too much accuracy needed.

CFR is still the best, however, like chess, we need a network that can help evaluate the position. Unlike chess, the hard part isn't knowing a value; it's knowing what the current game position is. For that, we need something unique.

I'm pretty convinced that this is solvable. I've been working on rs-poker for quite a while. Right now we have a whole multi-handed arena implemented, and a multi-threaded counterfactual framework (multi-threaded, with no memory fragmentation, and good cache coherency)

With BERT and some clever sequence encoding we can create a powerful agent. If anyone is interested, my email is: elliott.neil.clark@gmail.com