Also, I just thought of this.
But it's really no surprise that 29 took 90 chapters to agree to let Joseph go to TWTNW with Riku and everyone else when they went on their little raids. In fact, it's more of a surprise that he actually did let Joseph go to TWTNW in ch 90-94 (when they find Toby).
Because 29 has kept Joseph in CO for the past three months, at least. He has kept him as far away from TWTNW as it is possible because Saix is there. And going to TWTNW is possibly the last thing Joseph would ever do, because if he ran into Saix, he would be dead.
Which makes it even more surprising that 29 let's Joseph go off on his own to cause a distraction. I'm sure he trusts Joseph enough to run when there's trouble, but it can't have been easy for him, agreeing to that. I bet it took Joseph more than two hours to wear him down, and even then, it might've taken the fact that Joseph was needed to help the Rebellion to make 29 agree.
I actually doubt he'd have agreed otherwise. Or that he'll ever let Joseph go to TWTNW again. (At least not while Saix is breathing.)
Just wanted to throw this out here.