Yes, it's not meant to be production ready. Still, the padding you added is particular to Intel/AMD CPUs and this article is more about constrained memory/embedded.

On Intel you would not care about the missing slot when you have 256GB memory available.

I've added the atomic<> in the github and updated the article as well.

However with atomic<> it adds an mfence instruction which is not really necessary and might add a ton of latency.