well, I was thinking more in using more than one ES instances on the same machine listening on different ports, but your points on the other reply still apply.
I actually did that once - splitting one NUMA machine into 2 ES instances each isolated to its own socket (numactl etc).
Sadly at the time there was a big perf problem with indexingdocuments with 20kb+ binary blobs (non-indexed field) and so the change to 2 nodes vs one did have little noticeable effect on the throughput benchmarks I did with our data back then (~2015 ES 1.4) In the end I dropped this split and focused on the other bigger problems.
Would love to revisit this exercise with more of free time and better tools.