I'm working with some fbx models from Cinema 4D that were exported with the materials, so there is a shop_materialpath primitive attribute when importing them. I want to do some POPnet duplication simming (lots of copy to points) and then export as an .abc that so it can be used in C4D, Maya, whatever, with the material selections intact. I think my searching has gotten me close but I'm missing something--on the alembic ROP output I checked "build hierarchy from attribute" and put shop_materialpath as the attribute, but it's not doing the trick. I don't have or know C4D, so I'm checking my work in Maya, but I know from bringing the original fbxs into Maya that it should show up as a bunch of different materials in the hypershade, and that is lost on my exports. What step am I skipping (or doing wrong)?

(Also, apologies if I simply missed Just the Right Search to find the answer here--I've done a lot of digging, but I can't find the milk in the fridge, either, so I could have overlooked it.)