Please also keep in mind plans for using the “new” PPX abstraction layer, which is based somewhat on the ppxlib interface (see the announce at this forum - The future of ppx).
For deriving plugins see those:
- PR - ppx_deriving.* port to ppxlib (from ppx_tools)
- PR - ppx_deriving.yojson port to ppxlib (from ppx_tools)
- Issue - ppx_deriving.protobuf port to ppxlib (from ppx_tools)
So please keep those in mind, maybe help to review or update the PRs, and work on the protobuf one.