streamline multi-fits, determine 'best fit'

[jeffjennings]

Is your feature request related to a problem? Please describe -
Performing multiple fits in which the hyperparameters are varied is somewhat manual, when it could be entirely automated.

Describe the solution you'd like -
Use preprocess_visibilities to speed up a multiple fitting routine that performs fits over a grid of alpha and wsmooth.

Ideally this would also leverage a fitting approach that achieves convergence in a few iterations.

Further if a 'best fit' could be autonomously determined based on a couple of basic metrics, it would be ideal to provide this to a user.

Describe alternatives you've considered -
n/a

Additional context -
n/a