Multicore OCaml: Feb 2020 update

Hi Anil (or anyone!). Is there a place I can find more about breaking changes that might be made to C extensions? As you may know we have a lot of C code which interfaces with OCaml, both as ordinary extensions written in C, but also embedding OCaml in C programs (although that’s much more rare), and I’d like a heads up about what’s likely to change.