Interesting, thanks! PUT is advertised at 3500/s, so with a combo load, you were at least within range of advertised limits. I have not approached that scale so didn't know, it was a real question!
Yeah I was processing a bunch of iceberg catalog data, it was pretty trivial to get to this point on both PUTs and GETs with our data volume, I was doing 400,000 requests/m and of course my testing was writing to one prefix :)