-bin-annot too complicated?
What about core libraries? It looks no trivial to me to dive into the core build system to understand where to add -bin-annot. From your own description: "Where to add -bin-annot, depends on the build system". If its that complicated to get the desired result why don't you just publish a very simple patch for ocaml compiler which sets the option based on env var? export OCAML_BIN_ANNOT=1 and be done ? Stop caring about makefiles etc? And do the same for annot.