Train ArcFace on VGGFace2 dataset

I am trying to train a ResNet-34 on the VGGFace2 dataset using ArcFace loss (custom Keras implementation), but I can not get better results than regular Softmax Cross-Entropy loss.

In the published ArcFace paper, on Table 7, you report the results of a (VGG2, R50, ArcFace) model which I am trying to replicate, but you do not specify anywhere the paper the training arguments / hyperparameters when training on VGG2, other than m=0.3, and I can not find them anywhere in this repo.

Can anyone please tell me where can I find them (learning rate, steps, dropout, preprocessing, etc)