sometimes when i download several related articles (for instance, a primary journal article and a handful of commentary or news articles about it), i like to use the 'related' feature to crosslink them for later discoverability. it's suboptimal to go into each reference and add the others, or even to add the primary paper as the 'related' item for each of the secondary pieces. it would be super to be able to highlight the group and hit a "batch relate" button that would put each paper in each other's related column, or to highlight all the secondaries and batch-add the primary to all of them at once.