I got the idea his BB_2 is different. He's referring to a super Turing machine that can solve the halting problem for non-super Turing machines.
The BB-2 used in an iterative algorithm is talking about "A busy beaver number of (A busy beaver number of 10)", no need for super machines here. The iterative algorithm is short enough you can define it in your 1000 characters, no need for additional publication.