If I refer to my own experience as a noob, my first inclination when wanting to know what add-ons to use was to use Package Management, just as the DOCUMENTATION says. Which was fine, you need an app, you go to the app store. My issues were never naming conventions, though it helped to give me an idea. The issues were always real s$#%y descriptions and poor search within the manager. I think what would greatly help newbies is to continue streamlining the categorization but also set in place a standard for how extras are added.
Creating an extra tab for "under development" extras may help the confusion, a lot of times when I couldn't find an extra that was stable, I would get a little nervous using an alpha, beta, or RC extra. There should be a separation because of course you never use a testing extra in a live build. Removing versions from the extra's title would be good as well, add the version to a description place holder.
Also short and succinct descriptions would help, like this for Quip "A simple commenting system for MODx Revolution, complete with a backend management interface. Handles threaded and flat comments, with moderation, email notification, and more." Here if I found this under 'Commenting', the name wouldn't matter, I would know exactly what it does and what name to refer to if I needed support. This however, "getResources is a general-purpose listing and summarization snippet for MODx Revolution. It is NOT a replacement for Ditto, but rather an alternative component that can accomplish some of the things that the more specialized components do, i.e. Ditto, Wayfinder, Breadcrumbs; basically anything that output the properties for a list of Resources (formerly Documents in MODx Evolution).", is not helpful because it is jumbling it all with references to other builds and other extras. I had no idea what all the references were talking about as a newb.
I am all for unique (since getRelated was my idea

), but if we are expecting to expand MODX's popularity, we need to quit treating it like an exclusive club of special terms.