Many second-order optimizers aim to whiten the gradient, which scales each direction in the gradient to unit length. But why is this useful?

In a world of tuning I wanted to see how PSGD kron would fair without any tuning whatsoever on some Atari RL. I plugged it into CleanRL PPO with defaults and same LR as adam and it did quite well, check out some graphs! W&B report: api.wandb.ai/links/evanat...