the benefit of the start center is that you - have previews of the recent files - can open templates - open remote files - open new clean files for differnet apps so the goal of the start center is that the user get an good overview of the libreoffice files and projects. in toolbars (explicit the contextual toolbars) it is very importend to save space and as you has a much better overview when add an .uni:StartCenter action icon than add an open, new, recent, remote, ... action icon it would be awesome to have an StartCenter action available.
valuable enhancement request. status NEW
*** This bug has been marked as a duplicate of bug 77590 ***