Does Mantis offer any commentaries by early church fathers, e.g. Polycarp, Tertullian, Julius Africanus, Ignatius, Origen, Clement and others? If not, could we pursue some of the material from early church fathers for inclusion in Mantis. I am interested in comparing their point of view with reformation-era, and then later commentators.

I'm not sure if these are helpful, but check out
HOCC History of the Christian Church
NECF Nicene Early Church Fathers 14 Volume Set