Many ways to regulate that. For instance, require tracking of GPUs and that they must connect to centralized servers for certain workloads. Or just go ahead and nationalize and shutdown NVDA.
(And no, fine-tuning LAMA based models is not state of the art, and is not where the real progress is going to come from)
And even if all the regulation does is slow down progress, every extra year we get before recursively self improving AGI increases the chances of some critical advance in alignment and improves our chances a little bit.