For now, the library only supports reduction='mean'. We rely on the user to use this reduction and raise awareness about this point in the documentation. It would be better to automatically have the library detect the reduction and error if it is unsupported.
This can be done via a hook into BackPACK.
Implement hook that determines the loss function reduction during backpropagation
Integrate the above hook into the *Computation and raise an exception if the reduction is not supported
Remove the comments about supported reductions in the documentation
The docs show how to calculate the gram matrix eigenvectors and the paper articulates that to translate from 'gram space' to parameter space we just need to multiply by the 'V' matrix.