While I didn't try to use Docker (though we did use the same pxhere image :-p), I also struggled to get a productive setup of OCaml. Getting a switch running wasn't the hard part, it was making the environment suitable for real project work. I had a set of Make targets in mind (test, build, shell), some language dev features I wanted (jump to definition, type of expression under cursor), and some properties of the project (pinned dependencies) such that it took a fair bit of fiddling with dune/opam to get it working
https://morepablo.com/2019/08/fresco-jesus-ocaml-setup.htmlI find OCaml really enjoyable once I got going, but I do think the initial setup is a major barrier to larger adoption. I think a post on howistart.org might be useful, but it'd probably be polarizing since most functions have two major ways of doing it (Jane Street vs. not, Lwt vs. Async, etc.).