I think maybe he was the BO of /thestorm on 8chan when Q moved to a different 8chan board, /greatawakening, on Jan 8 2018. Not sure. But if so, he's probably bitter about that. The only thing I know for sure is that he now archives bdanon posts from 4chan on his own website.
Either way, I will ignore anything he says just based on his tweet that you posted.
Maybe someone else can tell you more.
Ah ok.
Post 515 was on /thestorm. That board only lasted a couple days before Q moved to /greatawakening.
Q had left /cbts on Jan 6 2018 in his last post there, number 473.
I do read the bdanon posts to keep informed of all the angles, keeping in mind the concept "Be careful who you follow" and "Disinfo is necessary." I personally think his posts could be from another white hat team not working with or against Q team and fulfilling a different purpose, focusing on different topics, and reaching a different audience. But just so you know, it seems many anons don't even like his name to be mentioned here, and respond with cursing when someone brings it up.