Looking great! I'm guessing you know this, having read the thread, but in case not - it's a little ridiculous how much tamping can be needed to lay out a stone floor like this so you remain happy with it over time. Human-level "seems pretty solid to me!", lacking experience, has no bearing whatsoever on the big and slow forces involved lol.

Edit: mulch over the sand under the rocks sounds sus, but I may have misunderstood. And to be clear, I'm far from an expert, learned how to do it "right" nearly a million years ago from an opinionated man (pops) who was legitimately excellent at things like this, and little else lol