When using butler export to save datasets to YAML, we tend to include relevant instrument dimensions such as instrument, physical_filter, and detector.

In many cases where you want to import into an existing repository we have already run butler register-instrument and these dimensions have already been defined. Import therefore fails. Currently we have to edit the YAML file. It would be nice if it was possible for either these instrument dimensions to be skipped (optionally) on export or else have the dimension duplication be ignored on import.

It's possible that skipping on import would be more robust.

I believe that currently skipping named dimensions on export is quite involved.