Each platform has their own rules for names, off the top of my head I don’t think X will allow registration of 4 (maybe 3) characters or less any longer, even i

Each platform has their own rules for names, off the top of my head I don’t think X will allow registration of 4 (maybe 3) characters or less any longer, even if it’s available. So without prying I couldn’t give you my opinion about your mark(s). In the case of X, I can use wayback machine and show the username did exist for a month when the platform launched (2006 I think) and then was removed from that point to the present. YouTube handles are a new feature only about a year old, and I have been trying to register it from day 1, so I have personal knowledge the handle has never existed, and they also prevent registration of any variations @{trademark}001. I also have evidence that the other major platforms (Meta/Instagram/Threads, GitHub, Reddit, Twitch, TikTok, etc…) were reserving this trademark and released it to me upon showing I’m the trademark owner. It’s strong enough to bring a civil lawsuit where the standard is “more likely than not” anyway. Again I doubt they’d want any employee of consequence being deposed under oath and testifying why they reserved it and refuse to turn it over to the trademark owner as many others have done.