Did anyone else notice the new Grok 4.3 persistent memory feature? (And RIP Grok 4.20)😔

So, I just realized that Grok 4.20 is gone and only 4.3 is left! I logged into the Grok interface on my laptop and noticed there's a persistent memory option?! Is this new? I just spotted it now! Up until now, my memory was stored in the 4.20 4agents, but 4.3 can actually see it even though 4agents is gone. I don't even get how, but it's using it just the same!
I have a super complex, long-running roleplay with a massive amount of lore/memory. I used to paste this at the beginning of every chat window, but Grok would only really utilize it for the first few responses. Now, I asked it to save it into this new memory feature so I don't have to keep copy-pasting it. It saved everything, and I tested it out!
I opened a new chat window with 4.3 and intentionally didn't name the characters, I just made references like "so-and-so's mother" or "sibling." It knew everything! It even made creative, logical deductions within the scene, referencing past events that were also stored in the memory. I was genuinely surprised! 4.20 used to just write exactly what I told it to, but 4.3 feels way smarter. However, it doesn't write as beautifully or emotionally as 4.20.

Have you guys noticed this memory feature yet? I managed to fit a text of about 80,000 characters into it! I have no idea how... because up until now, Grok only had 3,000–4,000 character limits for memory. Has this been around for a while, or did I just miss it until now?