The linked paper tested nanoGPT with this new transformer:
https://www.techrxiv.org/users/685780/articles/1375955-topol...
https://www.techrxiv.org/users/685780/articles/1375955-topol...
Yes the paper compares the new architecture (that is also a fork of my implementation of nanoGPT) with Karpathy's nanoGPT. There are also links to the code and bench used.
Transformers are universal function approximators. When well-tuned, they often start to approximate other innovations. Not always, thank god, but often enough that you have to be careful.