[cess11]

By "at the same time" do you mean that the execution starts at exactly the same time on two adjacent cores, or do you mean that they might as well be in the same queue and done sequentially?

What do you mean by "tightly interleaving"? It sounds like a technical term of some importance but when I web search it seems people are saying it means that the order of execution or data access is arbitrary, which you can let the built-in preemptive multitasking or a queue with a worker pool figure out for you.

In the alternatives you have in mind, how good is the monitoring, observability and IPC tooling? What's their hardware clustering story? I've done IPC in POSIX and that was absolutely dreadful so I hope you're working with something better than that at least.