Timeline (Beta) when collapsing groups - keep the overall timeline instead of loosing all visibility.

Timeline (Beta) when collapsing groups in the timelines it would be good if , instead of the current behaviour of removing all rows in that group from the visible timeline  there was a new behaviour of showing just 1 header line that encompassed the full span of any dates of the items in that group.    or for bonus points the ability to choose which default behaviour you want in the timeline settings.