Sorry to revive that old thread, but nothing has changed since last time, and the frame by frame orbx is just a temporary fix, not efficient at all: It replicates the textures and unchanged geometry for every frame, it can get heavy and be a lost of time.
Orbx is just a container, and it is possible to change the alembic after unpack. So why not export it right from the start?
The ideal solution would an option on the geometry object to force it to export the full sequence. We could get the best of both world this way.
It would be really helpful to us if you could work on it. (and the orbx import