I just see that the new Octane version support multiple UV. Will you update this exporter to manage this feature ? I know that OBJ don't support it but you spoke about some possible tricks :Octane tries to look for data that looks like additional UV sets in Alembic files and the plugins will have the possibility to export them, too, via the Octane API, but for now it's kinda tricky to use this feature if the source geometry doesn't supply multiple UV coordinates.
I am still more confortable with the standalone. I hope that it will be still possible to use it with multiple UV.
I had a look and the native Alembic exporter of C4D doesn't support multiple UVs. So there is no easy way to export multiple UVs right now.