Gamer's post-purchase add-ons, for short / SAT 11-18-23 / Certain descriptor after a signature nowadays / Brown-y points, for short? / Treatment for someone in transition, in brief

Downloadable content (DLC) is additional content created for an already released video game, distributed through the Internet by the game's publisher. It can either be added for no extra cost or it can be a form of video game monetization, enabling the publisher to gain additional revenue from a title after it has been purchased, often using some type of microtransaction system.

DLC can range from cosmetic content, such as skins, to new in-game content such as characters, levels, modes, and larger expansions that may contain a mix of such content as a continuation of the base game. In some games, multiple DLC (including future DLC not yet released) may be bundled as part of a "season pass"—typically at a discount in comparison to purchasing each DLC individually.

While the Dreamcast was the first home console to support DLC (albeit in a limited form due to hardware and internet connection limitations), Microsoft's Xbox console and Xbox Live platform helped to popularize the concept. Since the seventh generation of video game consoles, DLC has been a prevalent feature of most major video game platforms with internet connectivity.

Since the popularization of microtransactions in online distribution platforms such as Steam, the term DLC has become a [synonym] for any form of paid content in video games, regardless of whether they constitute the download of new content. Furthermore, this led to the creation of the oxymoronic term "on-disc DLC" for content included on the game's original files, but locked behind a paywall. (wikipedia)

The thing about DLC is, while you (or someone) might say "any gamer would know that," there's still the problem of non-gamers, and how in the world they would even begin to come at these three letters. It's the "Seemingly Random Three Letters" that is really the ugly, exclusionary part here. I think of all the garbage that clutters up the grid, so much of it 3-letter abbrs., and then I think "Why ... would you want to add to that?" Why would you want this Roman numeral-looking chunk of stray letters smack dab in the middle of your grid? Just because an answer is new (and this is, in fact, a debut answer) does not mean that it is "fresh" or "good." I do not mind learning new terminology, new slang, etc., but DLC is just ugly on its face—and the fact that its letters are barely inferable makes it uglier. I tried to figure out what the letters meant and the only thing I could come up with seemed way too vague to be right ... and yet it was. Downloadable Content. Where "Loadable" gets its own letter (?!). I don't think HRT (hormone replacement therapy) is great fill, but it's a thing anyone might have heard of, and its letters are reasonably inferable. Ditto CPU. I thinkSETI stands for Signs of Extraterrestrial Intelligence ... damn, it's "Search," not "Signs." Well, close enough. 

• 50D: The 411 (DEETS)— The 411, the information, the details ... the DEETS
• 28A: Brown-y points, for short? (TDS) — look, I'm just guessing here, but ... let's say Jim Brown? It's a weird clue, considering lots of Browns have been football stars. Antonio Brown, for instance, is a 7-time Pro Bowler. Tim Brown is in the Hall of Fame. Actually, I think the clue wants you to think of the team, the Cleveland Browns. "Brown-y points" is a pun that is both painful and unclear. 
• 62A: Sessions of congress? (TRYSTS)— So, "sexual congress," as the kids say nowadays
• 38D: Curing technique (DRY SALT) — "DRY-SALT" is a verb meaning "to cure or preserve (meat, hides, etc.) by drying and salting" (dictionary.com). "Dry curing" also appears to be a technique ... also involving salt ... and "dry brining," same ... they all seem like vaguely similar things? 
• 47A: Leaves for lunch, maybe (SALAD) — ah, the "Leaves" pun in the SALAD clue. An oldie but a goodie.
• 4D: Charybdis, for one (MAELSTROM) — whoo, this one is kinda hard! Everyone (give or take) is familiar with Scylla & Charybdis, but they're kinda used metaphorically. I don't think a Ton of thought is usually given to what *exactly* they are. I thought Charybdis was an underwater monster that *created* MALESTROMs (i.e. "large whirlpools capable of dragging a ship under water"). But wikipedia tells me that "In some variations of the story, Charybdis was simply a large whirlpool instead of a sea monster." So OK, I guess Charybdis = MAELSTROM does compute, then. See, I do like learning things! Destructive Like Charybdis! There's a DLC I can get behind.