Below is my plan for releases upgrade, would be happy to hear what you think.
We are going to support OCaml 4.06 and 4.02 at the same time for a while.
The corresponding version for bs-platform would be 5.(targeting 4.02 OCaml) and 6. (targeting 4.06)
5.* is recommended for production usage, bug fix is prioritized (tagged as beta-4.02 for pre-rleases)
6.* is expected to have some issues but encouraged to experiment until we make an official announcement it is great for production. (tagged as beta-4.06 for pre-releases)