BLT's 4-3 defensive playbook scheme, in the order he teaches it: settings, one macro, one coverage shell, one red-zone run fit, then a ranked game to prove it. The through-line is the same as his 4-2-5 Man Pressure ebook: don't blitz by default, make them beat a good user, and save the overload for third and long.
Patch timing (read this first). The video went up Aug 27 but was recorded earlier — at 23:45 he says the speed boost "hasn't been patched in this game when I'm recording this," and speed boosting was removed in the Aug 20 update. So the gameplay predates both Aug 20 and the Aug 27 Title Update 3.5 contain nerf. The settings, the overload macro, the Cover 3 Buzz shell, and the 6-1 run fit don't lean on the contain loop, so they should carry across. The one snap where he pairs Tampa 2 with QB contain + pass commit (29:09) is the pre-nerf version of that call — see Over G Cover 3 Sky for what post-patch pressure looks like.