Houdini user here. In Houdini when we load alembic files, it just reads from disk.
Meaning when you save your Houdini scene, the alembic won't increase the file size because it just reads it from disk.
In blender when I import my alembic scene, file becomes really big because it is saving the alembic in my blender file.
I found a work around, if I create a default cube and append a mesh sequence cache modifier then find my alembic cache/object path, it will reference rather than import. Once my scene is saved the .blend file will stay the same.
My question is why does this method work, but not the first method? They both do the same thing (assuming you have use mesh cache sequencer modifier enabled on alembic import settings).
Is there a way to get the importer to work in the way I want so I don't have to manually set it up?