I don't think it is possible. Kaguya had both powers and they were clearly manifested separately. It's thus impossible to predict what it may look like, since there's no underlying logic from which we could determine the look.
The lazy way would simply be to introduce the commas into a Byakugan.
Interesting enough, they did a Byaku-Sharingan design in Rock Lee's Springtime of Youth. Though it is comedy, I would recommend looking into it if that's something you are interested in. Check the Rock Lee's Springtime of Youth wiki for a picture.