Have you looked at "Emily" language at all? Same person or two, their original paper isn't reachable at their linked URL, but is on the Wayback Machine. "How Emily Tamed the Caml" - https://web.archive.org/web/20221231184748/https://www.hpl.h...

Emily took the approach of restricting a subset of OCaml, which they were running on Windows machines. No idea how tough it would be to get it running on a modern version.

Also for OCaml, the MirageOS unikernel is neat - develop on Linux etc., then recompile configured as a virtual machine with only the drivers (network, filesystem) needed by that one app. - https://mirage.io/