Option to mark a libary source a static

As many/some of us store media on e.g. a NAS it’s probably not uncommon to have ‘static folders/shares’ which are not expected to be updated and those who are expected to be updated. The process of updating metadata/scanning for new files could from this perspective be sped up when it’s possible to only ‘sync/populate’ the metadata of certain sources ‘once’. This could speed up updating/populating other sources. This to me ‘sounds’ like a relatively quick implementation to make. Of course the ‘Refresh Metadata’ option should show a popup asking whether to refresh ‘static’ sources when selecting it.