This
I support you 100% and am willing to help as well
Well it's little personal project all along and has been doing it for months now (thus it made me slow marking the mangas i've read) i use hashtags and little summaries to make it easy to search i'm telling you it's a totally daunting task. I'm currently slowly going back the earlier mangas i've read and do fixings. Check it http://www.mangago.zone/people/tag/49344/multiple+stories/
It's no limit now, takame-chan. Look at these summaries..
http://www.mangago.zone/read-manga/le_th_tre/
http://www.mangago.zone/read-manga/le_th_tre_de_b/
Aghhhh! I get so frustrated when I'm looking for a story that I know is in a multiple-story manga, but I can't remember the main title or author. So then when the summary is shortened (or missing), my search won't find the manga, dammit! I volunteer to help correct this, if anyone's paying attention...