Alembic Export skipping frames ???

[Gregory]

I think if you put an Edit Mesh modifier on the VRay Proxy object it'll render as a mesh, and should be renderable in Redshift...

Otherwise yes, you'd have to notify Autodesk about the bug.

Aha okay, will try that; thanks for the tip!
I'll talk to the team in any case; this is an embarrassment to have a broken alembic importer/exporter for so long.