Kelleytoons (5/14/2020)
You will not be able to get such custom eyebrows to follow -- the iClone/CC3 system of eye morphs means that only the base figure will change (and your eyebrows are "overlaid" onto that).
Conceivably you could perhaps bring over some eyebrow morphs for those custom eyebrows but you'd then have to hand key everything in (or perhaps find some Python way of doing it). Not worth the trouble, IMHO.
Thanks for letting me know. I was spending so much time searching for a solution but apparently there isn't one. Do you know if it is possible to create realistic hair/eyebrows/facial hair on CC3?