Investigate why filter tuning can be exceptionally slow for backends other than numpy.
Focus on matvec first.
Slowness persists when L1 is used as optimization measure instead of AUC for matvec, investigate potentially slow operations (e.g., indexing?) in that project.
Related tests: None (change backends in the current compare_filter_tuning.py in the playground)
Investigate why filter tuning can be exceptionally slow for backends other than numpy.
Related tests: None (change backends in the current compare_filter_tuning.py in the playground)