Minor suggestion Nicolas:

Currently, oc-natbib ignores global affixes.

This makes some sense given natbib has no notion of global vs per-cite
affixes.

But it seems ideally the code would preprend the global prefix to the local
prefix of the first cite.

So [cite:global ;local @doe] should yield \citep[global local ][]{doe}.

Not sure about suffixes; maybe (?) those are best ignored.

Bruce