Given the recent report on ppxlib, I thought it would be reasonable to bump/resurface this topic.
Since ppx’s objectives really are no longer in play, and the operationalized process is “option 2(b)” per @Chet_Murthy’s telling (but with patches coming out of some centralized process):
…it seems to me that there is a clear opening (as well as potential userbase) for something quite different from ppx that offers a simpler surface area, easier implementation, and more stable interface. Whether that implies a more rust-esque system or a source-to-source transliteration, there’s a lot of conceptual ground that is left uncovered by the current “blessed” spectrum of cppo/ppx.