I just want to clarify that it took me no more than a few hours to build the list I have, and from a dev perspective this involved writing a script to crawl the Tapas website, indexing all series with the tags nov18writerscamp into a database, building out a custom UI on the website to display the info from the database, and setting up server, hosting, domain etc.
Your works on Tapas are most certainly saved into a database the minute you create it, absolving the need for crawling and indexing. They already have formatting for collections (same as any other collection), and they already have server and hosting.
Tapas may well have their own reasons for not putting up the collections, but I doubt it's related to dev time. With all the stuff already set up, it ought to be as simple as writing a single database query and hooking it up to a new page, a matter of minutes. If it's not, I would be very worried about the state of Tapas' web stack.