> That's called beam search.

There are other decoding approaches, other than beam search:

https://arxiv.org/abs/2202.00666

> Other than that, things like gpt can't go back and edit what they've outputted

Actually, they can, they may emit a backspace token [1]

[1] https://arxiv.org/abs/2306.05426, https://news.ycombinator.com/item?id=36425375