The reading list page has 4 columns which can be used to sort series on the list. I don't know if this is actually an unintended feature but the untitled leftmost is the most useful to me. As I see it, it seems to sort based on the release date of the release in the "My Status". Sorting by chapter release dates was my expectation for how the "My Status" column should work, but it seems to only sort based on the release name instead. It would be nice if "My Status" column sorting behavior was changed to match the untitled leftmost column behavior, but that's not my main request. The leftmost button seems bugged since it only sorts in descending order with least recent releases at the top -> most recent releases at the bottom. I have a few series I keep up with as soon as they release, and a lot more which I'm ignoring till they're at a bigger build up and thus plan to read them later. I want those more recent releases (and by extension those series) to be at the top, so I don't have to scroll past all the series I'm trying to ignore. Coupled with my other feature request of persistent sorting, I'll be able to save and click and a scroll before I can jump right to the releases I care about.
The leftmost column isn't suppose to sort by any type of order that I know of. I think it's just random and you're just getting lucky. How big is your reading list? Anyways, this feature and http://forum.novelupdates.com/threads/persistent-sorting-setting-for-the-reading-list.62/ was listed in the old forums which I will try to move over this week. The reading list is the 2nd most visited page on my website (the main release page being #1) so of course its due for a major upgrade. I just need to implement some small stuff around the site first then I'll start working on it. I will try my best to fix the many flaws of this reading list
The behavior is really too consistent to be considered random, which is why I figured I lucked out with an unintended feature. I've experimented with it and the position of a series on the list can be moved up or down by changing the last release read. I think it's also actually the order in which the page loads, in that split second before alphabetical series name sort happens, so I suspect the manner in which the database filters/returns releases happens to be just what I want most - in reverse order. I'm at 65 releases, but I really only care about 10, up to 30 depending on my mood. I suppose what I really want is the ability to pin certain series to have them clearly set apart from from the others, but this recency based sorting is an acceptable replacement.