Questions about the size of the cascaded network model

[CGC1031]

Hello, as the cascade number increases, the model size should gradually increase, this can be seen on VTN network, but on VoxelMorph network why increase only 3MB each time, is the single VoxelMorph network parameter number is only 3MB?These are the size of the model after the training I think it's amazing.I really look forward to your help.
Thank you very much.