From what I've seen, some people update the episodes by adding pages afterwards and ticking the checkbox to notify subs. The other method is to later delete the separate pages and putting them all in one episode (which i think is kind of a shame since that gets rid of comments?).
The episode list can be annoying to navigate with older, longer comics. If you're looking for smth specific, an archive feature might be more useful. I haven't had a need to do that though.