Thank you. I will try your Chez idea. I love Chez, even if coding in Scheme can feel like rubbing sticks together to start a fire on an island, when e.g. Scala has induction ranges. And I didn't try Idris or Racket as they compile to Chez, but perhaps they do so better than I did.

As for parallelism this is a primary concern of mine, and I tried multiple approaches for every language where there was a choice. I used my own work-stealing code only when it beat standard libraries. AI warned me I was in over my head, that writing such a library takes years of experience, but my use case (and my expected use cases in my research) is so uniform that simple can win, minimally touching the required bases such as permuting tasks to avoid false sharing.

I don't believe that the JIT languages (F# on top) do so well because of better parallelism. This is branch optimization. For this use case an AOT compiler with ample benchmark data to influence output should do better. That isn't a thing, and the argument seems to be that few use cases stay consistent. A JIT can adapt.