Sabean and Omotic in cnetral Ethiopia and Eritrea?There is no modern group that is 100% proto-Cushitic without any non-Cushitic admixture. Bejas have mixed with Nubians, Egyptians, and Saudi type of Arabs (on their way inland into the rest of North Sudan during the Arabization period of Sudan).
Cushites more to the South often have local hunter-gatherer admixture and in Eritrea/North-Central Ethiopia they got Omotic & Habesha/Sabaean stuff.